In the Linux kernel, the following vulnerability has been resolved:
can: mcp251xfd: fix infinite loop when xmit fails
When the mcp251xfd_start_xmit() function fails, the driver stops
processing messages, and the interrupt routine does not return,
running indefinitely even after killing the running application.
Error messages:
[ 441.298819] mcp251xfd spi2.0 can0: ERROR in mcp251xfd_start_xmit: -16
[ 441.306498] mcp251xfd spi2.0 can0: Transmit Event FIFO buffer not empty. (seq=0x000017c7, tef_tail=0x000017cf, tef_head=0x000017d0, tx_head=0x000017d3).
... and repeat forever.
The issue can be triggered when multiple devices share the same SPI
interface. And there is concurrent access to the bus.
The problem occurs because tx_ring->head increments even if
mcp251xfd_start_xmit() fails. Consequently, the driver skips one TX
package while still expecting a response in
mcp251xfd_handle_tefif_one().
Resolve the issue by starting a workqueue to write the tx obj
synchronously if err = -EBUSY. In case of another error, decrement
tx_ring->head, remove skb from the echo stack, and drop the message.
[mkl: use more imperative wording in patch description]
In the Linux kernel, the following vulnerability has been resolved:
bcachefs: Fix sb_field_downgrade validation
- bch2_sb_downgrade_validate() wasn't checking for a downgrade entry
extending past the end of the superblock section
- for_each_downgrade_entry() is used in to_text() and needs to work on
malformed input; it also was missing a check for a field extending
past the end of the section
In the Linux kernel, the following vulnerability has been resolved:
net: can: j1939: enhanced error handling for tightly received RTS messages in xtp_rx_rts_session_new
This patch enhances error handling in scenarios with RTS (Request to
Send) messages arriving closely. It replaces the less informative WARN_ON_ONCE
backtraces with a new error handling method. This provides clearer error
messages and allows for the early termination of problematic sessions.
Previously, sessions were only released at the end of j1939_xtp_rx_rts().
Potentially this could be reproduced with something like:
testj1939 -r vcan0:0x80 &
while true; do
# send first RTS
cansend vcan0 18EC8090#1014000303002301;
# send second RTS
cansend vcan0 18EC8090#1014000303002301;
# send abort
cansend vcan0 18EC8090#ff00000000002301;
done
Twisted is an event-based framework for internet applications, supporting Python 3.6+. The HTTP 1.0 and 1.1 server provided by twisted.web could process pipelined HTTP requests out-of-order, possibly resulting in information disclosure. This vulnerability is fixed in 24.7.0rc1.
In the Linux kernel, the following vulnerability has been resolved:
nvme-fabrics: use reserved tag for reg read/write command
In some scenarios, if too many commands are issued by nvme command in
the same time by user tasks, this may exhaust all tags of admin_q. If
a reset (nvme reset or IO timeout) occurs before these commands finish,
reconnect routine may fail to update nvme regs due to insufficient tags,
which will cause kernel hang forever. In order to workaround this issue,
maybe we can let reg_read32()/reg_read64()/reg_write32() use reserved
tags. This maybe safe for nvmf:
1. For the disable ctrl path, we will not issue connect command
2. For the enable ctrl / fw activate path, since connect and reg_xx()
are called serially.
So the reserved tags may still be enough while reg_xx() use reserved tags.
In the Linux kernel, the following vulnerability has been resolved:
ila: block BH in ila_output()
As explained in commit 1378817486d6 ("tipc: block BH
before using dst_cache"), net/core/dst_cache.c
helpers need to be called with BH disabled.
ila_output() is called from lwtunnel_output()
possibly from process context, and under rcu_read_lock().
We might be interrupted by a softirq, re-enter ila_output()
and corrupt dst_cache data structures.
Fix the race by using local_bh_disable().
In the Linux kernel, the following vulnerability has been resolved:
io_uring: fix possible deadlock in io_register_iowq_max_workers()
The io_register_iowq_max_workers() function calls io_put_sq_data(),
which acquires the sqd->lock without releasing the uring_lock.
Similar to the commit 009ad9f0c6ee ("io_uring: drop ctx->uring_lock
before acquiring sqd->lock"), this can lead to a potential deadlock
situation.
To resolve this issue, the uring_lock is released before calling
io_put_sq_data(), and then it is re-acquired after the function call.
This change ensures that the locks are acquired in the correct
order, preventing the possibility of a deadlock.
In the Linux kernel, the following vulnerability has been resolved:
nvmet: always initialize cqe.result
The spec doesn't mandate that the first two double words (aka results)
for the command queue entry need to be set to 0 when they are not
used (not specified). Though, the target implemention returns 0 for TCP
and FC but not for RDMA.
Let's make RDMA behave the same and thus explicitly initializing the
result field. This prevents leaking any data from the stack.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: qgroup: fix quota root leak after quota disable failure
If during the quota disable we fail when cleaning the quota tree or when
deleting the root from the root tree, we jump to the 'out' label without
ever dropping the reference on the quota root, resulting in a leak of the
root since fs_info->quota_root is no longer pointing to the root (we have
set it to NULL just before those steps).
Fix this by always doing a btrfs_put_root() call under the 'out' label.
This is a problem that exists since qgroups were first added in 2012 by
commit bed92eae26cc ("Btrfs: qgroup implementation and prototypes"), but
back then we missed a kfree on the quota root and free_extent_buffer()
calls on its root and commit root nodes, since back then roots were not
yet reference counted.
In the Linux kernel, the following vulnerability has been resolved:
null_blk: fix validation of block size
Block size should be between 512 and PAGE_SIZE and be a power of 2. The current
check does not validate this, so update the check.
Without this patch, null_blk would Oops due to a null pointer deref when
loaded with bs=1536 [1].
[axboe: remove unnecessary braces and != 0 check]
In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix memory leak in nfs4_set_security_label
We leak nfs_fattr and nfs4_label every time we set a security xattr.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: add consistency check for copen/cread
This prevents malicious processes from completing random copen/cread
requests and crashing the system. Added checks are listed below:
* Generic, copen can only complete open requests, and cread can only
complete read requests.
* For copen, ondemand_id must not be 0, because this indicates that the
request has not been read by the daemon.
* For cread, the object corresponding to fd and req should be the same.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: Set object to close if ondemand_id < 0 in copen
If copen is maliciously called in the user mode, it may delete the request
corresponding to the random id. And the request may have not been read yet.
Note that when the object is set to reopen, the open request will be done
with the still reopen state in above case. As a result, the request
corresponding to this object is always skipped in select_req function, so
the read request is never completed and blocks other process.
Fix this issue by simply set object to close if its id < 0 in copen.
In the Linux kernel, the following vulnerability has been resolved:
nvme: avoid double free special payload
If a discard request needs to be retried, and that retry may fail before
a new special payload is added, a double free will result. Clear the
RQF_SPECIAL_LOAD when the request is cleaned.
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: wext: add extra SIOCSIWSCAN data check
In 'cfg80211_wext_siwscan()', add extra check whether number of
channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed
IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise.
In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()
Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().
It looks up `stt` from tablefd, but then continues to use it after doing
fdput() on the returned fd. After the fdput() the tablefd is free to be
closed by another thread. The close calls kvm_spapr_tce_release() and
then release_spapr_tce_table() (via call_rcu()) which frees `stt`.
Although there are calls to rcu_read_lock() in
kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent
the UAF, because `stt` is used outside the locked regions.
With an artifcial delay after the fdput() and a userspace program which
triggers the race, KASAN detects the UAF:
BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505
CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1
Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV
Call Trace:
dump_stack_lvl+0xb4/0x108 (unreliable)
print_report+0x2b4/0x6ec
kasan_report+0x118/0x2b0
__asan_load4+0xb8/0xd0
kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]
kvm_vfio_set_attr+0x524/0xac0 [kvm]
kvm_device_ioctl+0x144/0x240 [kvm]
sys_ioctl+0x62c/0x1810
system_call_exception+0x190/0x440
system_call_vectored_common+0x15c/0x2ec
...
Freed by task 0:
...
kfree+0xec/0x3e0
release_spapr_tce_table+0xd4/0x11c [kvm]
rcu_core+0x568/0x16a0
handle_softirqs+0x23c/0x920
do_softirq_own_stack+0x6c/0x90
do_softirq_own_stack+0x58/0x90
__irq_exit_rcu+0x218/0x2d0
irq_exit+0x30/0x80
arch_local_irq_restore+0x128/0x230
arch_local_irq_enable+0x1c/0x30
cpuidle_enter_state+0x134/0x5cc
cpuidle_enter+0x6c/0xb0
call_cpuidle+0x7c/0x100
do_idle+0x394/0x410
cpu_startup_entry+0x60/0x70
start_secondary+0x3fc/0x410
start_secondary_prolog+0x10/0x14
Fix it by delaying the fdput() until `stt` is no longer in use, which
is effectively the entire function. To keep the patch minimal add a call
to fdput() at each of the existing return paths. Future work can convert
the function to goto or __cleanup style cleanup.
With the fix in place the test case no longer triggers the UAF.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: topology: Fix references to freed memory
Most users after parsing a topology file, release memory used by it, so
having pointer references directly into topology file contents is wrong.
Use devm_kmemdup(), to allocate memory as needed.
In the Linux kernel, the following vulnerability has been resolved:
s390/sclp: Fix sclp_init() cleanup on failure
If sclp_init() fails it only partially cleans up: if there are multiple
failing calls to sclp_init() sclp_state_change_event will be added several
times to sclp_reg_list, which results in the following warning:
------------[ cut here ]------------
list_add double add: new=000003ffe1598c10, prev=000003ffe1598bf0, next=000003ffe1598c10.
WARNING: CPU: 0 PID: 1 at lib/list_debug.c:35 __list_add_valid_or_report+0xde/0xf8
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc3
Krnl PSW : 0404c00180000000 000003ffe0d6076a (__list_add_valid_or_report+0xe2/0xf8)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
...
Call Trace:
[<000003ffe0d6076a>] __list_add_valid_or_report+0xe2/0xf8
([<000003ffe0d60766>] __list_add_valid_or_report+0xde/0xf8)
[<000003ffe0a8d37e>] sclp_init+0x40e/0x450
[<000003ffe00009f2>] do_one_initcall+0x42/0x1e0
[<000003ffe15b77a6>] do_initcalls+0x126/0x150
[<000003ffe15b7a0a>] kernel_init_freeable+0x1ba/0x1f8
[<000003ffe0d6650e>] kernel_init+0x2e/0x180
[<000003ffe000301c>] __ret_from_fork+0x3c/0x60
[<000003ffe0d759ca>] ret_from_fork+0xa/0x30
Fix this by removing sclp_state_change_event from sclp_reg_list when
sclp_init() fails.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: scrub: handle RST lookup error correctly
[BUG]
When running btrfs/060 with forced RST feature, it would crash the
following ASSERT() inside scrub_read_endio():
ASSERT(sector_nr < stripe->nr_sectors);
Before that, we would have tree dump from
btrfs_get_raid_extent_offset(), as we failed to find the RST entry for
the range.
[CAUSE]
Inside scrub_submit_extent_sector_read() every time we allocated a new
bbio we immediately called btrfs_map_block() to make sure there was some
RST range covering the scrub target.
But if btrfs_map_block() fails, we immediately call endio for the bbio,
while the bbio is newly allocated, it's completely empty.
Then inside scrub_read_endio(), we go through the bvecs to find
the sector number (as bi_sector is no longer reliable if the bio is
submitted to lower layers).
And since the bio is empty, such bvecs iteration would not find any
sector matching the sector, and return sector_nr == stripe->nr_sectors,
triggering the ASSERT().
[FIX]
Instead of calling btrfs_map_block() after allocating a new bbio, call
btrfs_map_block() first.
Since our only objective of calling btrfs_map_block() is only to update
stripe_len, there is really no need to do that after btrfs_alloc_bio().
This new timing would avoid the problem of handling empty bbio
completely, and in fact fixes a possible race window for the old code,
where if the submission thread is the only owner of the pending_io, the
scrub would never finish (since we didn't decrease the pending_io
counter).
Although the root cause of RST lookup failure still needs to be
addressed.
In the Linux kernel, the following vulnerability has been resolved:
ibmvnic: Add tx check to prevent skb leak
Below is a summary of how the driver stores a reference to an skb during
transmit:
tx_buff[free_map[consumer_index]]->skb = new_skb;
free_map[consumer_index] = IBMVNIC_INVALID_MAP;
consumer_index ++;
Where variable data looks like this:
free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3]
consumer_index^
tx_buff == [skb=null, skb=<ptr>, skb=<ptr>, skb=null, skb=null]
The driver has checks to ensure that free_map[consumer_index] pointed to
a valid index but there was no check to ensure that this index pointed
to an unused/null skb address. So, if, by some chance, our free_map and
tx_buff lists become out of sync then we were previously risking an
skb memory leak. This could then cause tcp congestion control to stop
sending packets, eventually leading to ETIMEDOUT.
Therefore, add a conditional to ensure that the skb address is null. If
not then warn the user (because this is still a bug that should be
patched) and free the old pointer to prevent memleak/tcp problems.
In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries: Whitelist dtl slub object for copying to userspace
Reading the dispatch trace log from /sys/kernel/debug/powerpc/dtl/cpu-*
results in a BUG() when the config CONFIG_HARDENED_USERCOPY is enabled as
shown below.
kernel BUG at mm/usercopy.c:102!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc
scsi_transport_fc ibmveth pseries_wdt dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse
CPU: 27 PID: 1815 Comm: python3 Not tainted 6.10.0-rc3 #85
Hardware name: IBM,9040-MRX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_042) hv:phyp pSeries
NIP: c0000000005d23d4 LR: c0000000005d23d0 CTR: 00000000006ee6f8
REGS: c000000120c078c0 TRAP: 0700 Not tainted (6.10.0-rc3)
MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 2828220f XER: 0000000e
CFAR: c0000000001fdc80 IRQMASK: 0
[ ... GPRs omitted ... ]
NIP [c0000000005d23d4] usercopy_abort+0x78/0xb0
LR [c0000000005d23d0] usercopy_abort+0x74/0xb0
Call Trace:
usercopy_abort+0x74/0xb0 (unreliable)
__check_heap_object+0xf8/0x120
check_heap_object+0x218/0x240
__check_object_size+0x84/0x1a4
dtl_file_read+0x17c/0x2c4
full_proxy_read+0x8c/0x110
vfs_read+0xdc/0x3a0
ksys_read+0x84/0x144
system_call_exception+0x124/0x330
system_call_vectored_common+0x15c/0x2ec
--- interrupt: 3000 at 0x7fff81f3ab34
Commit 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0")
requires that only whitelisted areas in slab/slub objects can be copied to
userspace when usercopy hardening is enabled using CONFIG_HARDENED_USERCOPY.
Dtl contains hypervisor dispatch events which are expected to be read by
privileged users. Hence mark this safe for user access.
Specify useroffset=0 and usersize=DISPATCH_LOG_BYTES to whitelist the
entire object.
In the Linux kernel, the following vulnerability has been resolved:
powerpc/eeh: avoid possible crash when edev->pdev changes
If a PCI device is removed during eeh_pe_report_edev(), edev->pdev
will change and can cause a crash, hold the PCI rescan/remove lock
while taking a copy of edev->pdev->bus.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: cancel all works upon hci_unregister_dev()
syzbot is reporting that calling hci_release_dev() from hci_error_reset()
due to hci_dev_put() from hci_error_reset() can cause deadlock at
destroy_workqueue(), for hci_error_reset() is called from
hdev->req_workqueue which destroy_workqueue() needs to flush.
We need to make sure that hdev->{rx_work,cmd_work,tx_work} which are
queued into hdev->workqueue and hdev->{power_on,error_reset} which are
queued into hdev->req_workqueue are no longer running by the moment
destroy_workqueue(hdev->workqueue);
destroy_workqueue(hdev->req_workqueue);
are called from hci_release_dev().
Call cancel_work_sync() on these work items from hci_unregister_dev()
as soon as hdev->list is removed from hci_dev_list.
In the Linux kernel, the following vulnerability has been resolved:
bluetooth/l2cap: sync sock recv cb and release
The problem occurs between the system call to close the sock and hci_rx_work,
where the former releases the sock and the latter accesses it without lock protection.
CPU0 CPU1
---- ----
sock_close hci_rx_work
l2cap_sock_release hci_acldata_packet
l2cap_sock_kill l2cap_recv_frame
sk_free l2cap_conless_channel
l2cap_sock_recv_cb
If hci_rx_work processes the data that needs to be received before the sock is
closed, then everything is normal; Otherwise, the work thread may access the
released sock when receiving data.
Add a chan mutex in the rx callback of the sock to achieve synchronization between
the sock release and recv cb.
Sock is dead, so set chan data to NULL, avoid others use invalid sock pointer.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix array-index-out-of-bounds in dml2/FCLKChangeSupport
[Why]
Potential out of bounds access in dml2_calculate_rq_and_dlg_params()
because the value of out_lowest_state_idx used as an index for FCLKChangeSupport
array can be greater than 1.
[How]
Currently dml2 core specifies identical values for all FCLKChangeSupport
elements. Always use index 0 in the condition to avoid out of bounds access.
In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: check bo_va->bo is non-NULL before using it
The call to radeon_vm_clear_freed might clear bo_va->bo, so
we have to check it before dereferencing it.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix slab-use-after-free in fscache_withdraw_volume()
We got the following issue in our fault injection stress test:
==================================================================
BUG: KASAN: slab-use-after-free in fscache_withdraw_volume+0x2e1/0x370
Read of size 4 at addr ffff88810680be08 by task ondemand-04-dae/5798
CPU: 0 PID: 5798 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #565
Call Trace:
kasan_check_range+0xf6/0x1b0
fscache_withdraw_volume+0x2e1/0x370
cachefiles_withdraw_volume+0x31/0x50
cachefiles_withdraw_cache+0x3ad/0x900
cachefiles_put_unbind_pincount+0x1f6/0x250
cachefiles_daemon_release+0x13b/0x290
__fput+0x204/0xa00
task_work_run+0x139/0x230
Allocated by task 5820:
__kmalloc+0x1df/0x4b0
fscache_alloc_volume+0x70/0x600
__fscache_acquire_volume+0x1c/0x610
erofs_fscache_register_volume+0x96/0x1a0
erofs_fscache_register_fs+0x49a/0x690
erofs_fc_fill_super+0x6c0/0xcc0
vfs_get_super+0xa9/0x140
vfs_get_tree+0x8e/0x300
do_new_mount+0x28c/0x580
[...]
Freed by task 5820:
kfree+0xf1/0x2c0
fscache_put_volume.part.0+0x5cb/0x9e0
erofs_fscache_unregister_fs+0x157/0x1b0
erofs_kill_sb+0xd9/0x1c0
deactivate_locked_super+0xa3/0x100
vfs_get_super+0x105/0x140
vfs_get_tree+0x8e/0x300
do_new_mount+0x28c/0x580
[...]
==================================================================
Following is the process that triggers the issue:
mount failed | daemon exit
------------------------------------------------------------
deactivate_locked_super cachefiles_daemon_release
erofs_kill_sb
erofs_fscache_unregister_fs
fscache_relinquish_volume
__fscache_relinquish_volume
fscache_put_volume(fscache_volume, fscache_volume_put_relinquish)
zero = __refcount_dec_and_test(&fscache_volume->ref, &ref);
cachefiles_put_unbind_pincount
cachefiles_daemon_unbind
cachefiles_withdraw_cache
cachefiles_withdraw_volumes
list_del_init(&volume->cache_link)
fscache_free_volume(fscache_volume)
cache->ops->free_volume
cachefiles_free_volume
list_del_init(&cachefiles_volume->cache_link);
kfree(fscache_volume)
cachefiles_withdraw_volume
fscache_withdraw_volume
fscache_volume->n_accesses
// fscache_volume UAF !!!
The fscache_volume in cache->volumes must not have been freed yet, but its
reference count may be 0. So use the new fscache_try_get_volume() helper
function try to get its reference count.
If the reference count of fscache_volume is 0, fscache_put_volume() is
freeing it, so wait for it to be removed from cache->volumes.
If its reference count is not 0, call cachefiles_withdraw_volume() with
reference count protection to avoid the above issue.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()
We got the following issue in our fault injection stress test:
==================================================================
BUG: KASAN: slab-use-after-free in cachefiles_withdraw_cookie+0x4d9/0x600
Read of size 8 at addr ffff888118efc000 by task kworker/u78:0/109
CPU: 13 PID: 109 Comm: kworker/u78:0 Not tainted 6.8.0-dirty #566
Call Trace:
<TASK>
kasan_report+0x93/0xc0
cachefiles_withdraw_cookie+0x4d9/0x600
fscache_cookie_state_machine+0x5c8/0x1230
fscache_cookie_worker+0x91/0x1c0
process_one_work+0x7fa/0x1800
[...]
Allocated by task 117:
kmalloc_trace+0x1b3/0x3c0
cachefiles_acquire_volume+0xf3/0x9c0
fscache_create_volume_work+0x97/0x150
process_one_work+0x7fa/0x1800
[...]
Freed by task 120301:
kfree+0xf1/0x2c0
cachefiles_withdraw_cache+0x3fa/0x920
cachefiles_put_unbind_pincount+0x1f6/0x250
cachefiles_daemon_release+0x13b/0x290
__fput+0x204/0xa00
task_work_run+0x139/0x230
do_exit+0x87a/0x29b0
[...]
==================================================================
Following is the process that triggers the issue:
p1 | p2
------------------------------------------------------------
fscache_begin_lookup
fscache_begin_volume_access
fscache_cache_is_live(fscache_cache)
cachefiles_daemon_release
cachefiles_put_unbind_pincount
cachefiles_daemon_unbind
cachefiles_withdraw_cache
fscache_withdraw_cache
fscache_set_cache_state(cache, FSCACHE_CACHE_IS_WITHDRAWN);
cachefiles_withdraw_objects(cache)
fscache_wait_for_objects(fscache)
atomic_read(&fscache_cache->object_count) == 0
fscache_perform_lookup
cachefiles_lookup_cookie
cachefiles_alloc_object
refcount_set(&object->ref, 1);
object->volume = volume
fscache_count_object(vcookie->cache);
atomic_inc(&fscache_cache->object_count)
cachefiles_withdraw_volumes
cachefiles_withdraw_volume
fscache_withdraw_volume
__cachefiles_free_volume
kfree(cachefiles_volume)
fscache_cookie_state_machine
cachefiles_withdraw_cookie
cache = object->volume->cache;
// cachefiles_volume UAF !!!
After setting FSCACHE_CACHE_IS_WITHDRAWN, wait for all the cookie lookups
to complete first, and then wait for fscache_cache->object_count == 0 to
avoid the cookie exiting after the volume has been freed and triggering
the above issue. Therefore call fscache_withdraw_volume() before calling
cachefiles_withdraw_objects().
This way, after setting FSCACHE_CACHE_IS_WITHDRAWN, only the following two
cases will occur:
1) fscache_begin_lookup fails in fscache_begin_volume_access().
2) fscache_withdraw_volume() will ensure that fscache_count_object() has
been executed before calling fscache_wait_for_objects().
In the Linux kernel, the following vulnerability has been resolved:
firmware: cs_dsp: Use strnlen() on name fields in V1 wmfw files
Use strnlen() instead of strlen() on the algorithm and coefficient name
string arrays in V1 wmfw files.
In V1 wmfw files the name is a NUL-terminated string in a fixed-size
array. cs_dsp should protect against overrunning the array if the NUL
terminator is missing.
In the Linux kernel, the following vulnerability has been resolved:
mm: prevent derefencing NULL ptr in pfn_section_valid()
Commit 5ec8e8ea8b77 ("mm/sparsemem: fix race in accessing
memory_section->usage") changed pfn_section_valid() to add a READ_ONCE()
call around "ms->usage" to fix a race with section_deactivate() where
ms->usage can be cleared. The READ_ONCE() call, by itself, is not enough
to prevent NULL pointer dereference. We need to check its value before
dereferencing it.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: wait for ondemand_object_worker to finish when dropping object
When queuing ondemand_object_worker() to re-open the object,
cachefiles_object is not pinned. The cachefiles_object may be freed when
the pending read request is completed intentionally and the related
erofs is umounted. If ondemand_object_worker() runs after the object is
freed, it will incur use-after-free problem as shown below.
process A processs B process C process D
cachefiles_ondemand_send_req()
// send a read req X
// wait for its completion
// close ondemand fd
cachefiles_ondemand_fd_release()
// set object as CLOSE
cachefiles_ondemand_daemon_read()
// set object as REOPENING
queue_work(fscache_wq, &info->ondemand_work)
// close /dev/cachefiles
cachefiles_daemon_release
cachefiles_flush_reqs
complete(&req->done)
// read req X is completed
// umount the erofs fs
cachefiles_put_object()
// object will be freed
cachefiles_ondemand_deinit_obj_info()
kmem_cache_free(object)
// both info and object are freed
ondemand_object_worker()
When dropping an object, it is no longer necessary to reopen the object,
so use cancel_work_sync() to cancel or wait for ondemand_object_worker()
to finish.
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: cyclic allocation of msg_id to avoid reuse
Reusing the msg_id after a maliciously completed reopen request may cause
a read request to remain unprocessed and result in a hung, as shown below:
t1 | t2 | t3
-------------------------------------------------
cachefiles_ondemand_select_req
cachefiles_ondemand_object_is_close(A)
cachefiles_ondemand_set_object_reopening(A)
queue_work(fscache_object_wq, &info->work)
ondemand_object_worker
cachefiles_ondemand_init_object(A)
cachefiles_ondemand_send_req(OPEN)
// get msg_id 6
wait_for_completion(&req_A->done)
cachefiles_ondemand_daemon_read
// read msg_id 6 req_A
cachefiles_ondemand_get_fd
copy_to_user
// Malicious completion msg_id 6
copen 6,-1
cachefiles_ondemand_copen
complete(&req_A->done)
// will not set the object to close
// because ondemand_id && fd is valid.
// ondemand_object_worker() is done
// but the object is still reopening.
// new open req_B
cachefiles_ondemand_init_object(B)
cachefiles_ondemand_send_req(OPEN)
// reuse msg_id 6
process_open_req
copen 6,A.size
// The expected failed copen was executed successfully
Expect copen to fail, and when it does, it closes fd, which sets the
object to close, and then close triggers reopen again. However, due to
msg_id reuse resulting in a successful copen, the anonymous fd is not
closed until the daemon exits. Therefore read requests waiting for reopen
to complete may trigger hung task.
To avoid this issue, allocate the msg_id cyclically to avoid reusing the
msg_id for a very short duration of time.
In the Linux kernel, the following vulnerability has been resolved:
filelock: fix potential use-after-free in posix_lock_inode
Light Hsieh reported a KASAN UAF warning in trace_posix_lock_inode().
The request pointer had been changed earlier to point to a lock entry
that was added to the inode's list. However, before the tracepoint could
fire, another task raced in and freed that lock.
Fix this by moving the tracepoint inside the spinlock, which should
ensure that this doesn't happen.
In the Linux kernel, the following vulnerability has been resolved:
skmsg: Skip zero length skb in sk_msg_recvmsg
When running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch
platform, the following kernel panic occurs:
[...]
Oops[#1]:
CPU: 22 PID: 2824 Comm: test_progs Tainted: G OE 6.10.0-rc2+ #18
Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018
... ...
ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560
ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0
CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
PRMD: 0000000c (PPLV0 +PIE +PWE)
EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
BADV: 0000000000000040
PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)
Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack
Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)
Stack : ...
Call Trace:
[<9000000004162774>] copy_page_to_iter+0x74/0x1c0
[<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560
[<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0
[<90000000049aae34>] inet_recvmsg+0x54/0x100
[<900000000481ad5c>] sock_recvmsg+0x7c/0xe0
[<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0
[<900000000481e27c>] sys_recvfrom+0x1c/0x40
[<9000000004c076ec>] do_syscall+0x8c/0xc0
[<9000000003731da4>] handle_syscall+0xc4/0x160
Code: ...
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception
Kernel relocated by 0x3510000
.text @ 0x9000000003710000
.data @ 0x9000000004d70000
.bss @ 0x9000000006469400
---[ end Kernel panic - not syncing: Fatal exception ]---
[...]
This crash happens every time when running sockmap_skb_verdict_shutdown
subtest in sockmap_basic.
This crash is because a NULL pointer is passed to page_address() in the
sk_msg_recvmsg(). Due to the different implementations depending on the
architecture, page_address(NULL) will trigger a panic on Loongarch
platform but not on x86 platform. So this bug was hidden on x86 platform
for a while, but now it is exposed on Loongarch platform. The root cause
is that a zero length skb (skb->len == 0) was put on the queue.
This zero length skb is a TCP FIN packet, which was sent by shutdown(),
invoked in test_sockmap_skb_verdict_shutdown():
shutdown(p1, SHUT_WR);
In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no
page is put to this sge (see sg_set_page in sg_set_page), but this empty
sge is queued into ingress_msg list.
And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by
sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it
to kmap_local_page() and to page_address(), then kernel panics.
To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),
if copy is zero, that means it's a zero length skb, skip invoking
copy_page_to_iter(). We are using the EFAULT return triggered by
copy_page_to_iter to check for is_fin in tcp_bpf.c.
In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix XDP program unloading while removing the driver
The commit 6533e558c650 ("i40e: Fix reset path while removing
the driver") introduced a new PF state "__I40E_IN_REMOVE" to block
modifying the XDP program while the driver is being removed.
Unfortunately, such a change is useful only if the ".ndo_bpf()"
callback was called out of the rmmod context because unloading the
existing XDP program is also a part of driver removing procedure.
In other words, from the rmmod context the driver is expected to
unload the XDP program without reporting any errors. Otherwise,
the kernel warning with callstack is printed out to dmesg.
Example failing scenario:
1. Load the i40e driver.
2. Load the XDP program.
3. Unload the i40e driver (using "rmmod" command).
The example kernel warning log:
[ +0.004646] WARNING: CPU: 94 PID: 10395 at net/core/dev.c:9290 unregister_netdevice_many_notify+0x7a9/0x870
[...]
[ +0.010959] RIP: 0010:unregister_netdevice_many_notify+0x7a9/0x870
[...]
[ +0.002726] Call Trace:
[ +0.002457] <TASK>
[ +0.002119] ? __warn+0x80/0x120
[ +0.003245] ? unregister_netdevice_many_notify+0x7a9/0x870
[ +0.005586] ? report_bug+0x164/0x190
[ +0.003678] ? handle_bug+0x3c/0x80
[ +0.003503] ? exc_invalid_op+0x17/0x70
[ +0.003846] ? asm_exc_invalid_op+0x1a/0x20
[ +0.004200] ? unregister_netdevice_many_notify+0x7a9/0x870
[ +0.005579] ? unregister_netdevice_many_notify+0x3cc/0x870
[ +0.005586] unregister_netdevice_queue+0xf7/0x140
[ +0.004806] unregister_netdev+0x1c/0x30
[ +0.003933] i40e_vsi_release+0x87/0x2f0 [i40e]
[ +0.004604] i40e_remove+0x1a1/0x420 [i40e]
[ +0.004220] pci_device_remove+0x3f/0xb0
[ +0.003943] device_release_driver_internal+0x19f/0x200
[ +0.005243] driver_detach+0x48/0x90
[ +0.003586] bus_remove_driver+0x6d/0xf0
[ +0.003939] pci_unregister_driver+0x2e/0xb0
[ +0.004278] i40e_exit_module+0x10/0x5f0 [i40e]
[ +0.004570] __do_sys_delete_module.isra.0+0x197/0x310
[ +0.005153] do_syscall_64+0x85/0x170
[ +0.003684] ? syscall_exit_to_user_mode+0x69/0x220
[ +0.004886] ? do_syscall_64+0x95/0x170
[ +0.003851] ? exc_page_fault+0x7e/0x180
[ +0.003932] entry_SYSCALL_64_after_hwframe+0x71/0x79
[ +0.005064] RIP: 0033:0x7f59dc9347cb
[ +0.003648] Code: 73 01 c3 48 8b 0d 65 16 0c 00 f7 d8 64 89 01 48 83
c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 35 16 0c 00 f7 d8 64 89 01 48
[ +0.018753] RSP: 002b:00007ffffac99048 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ +0.007577] RAX: ffffffffffffffda RBX: 0000559b9bb2f6e0 RCX: 00007f59dc9347cb
[ +0.007140] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000559b9bb2f748
[ +0.007146] RBP: 00007ffffac99070 R08: 1999999999999999 R09: 0000000000000000
[ +0.007133] R10: 00007f59dc9a5ac0 R11: 0000000000000206 R12: 0000000000000000
[ +0.007141] R13: 00007ffffac992d8 R14: 0000559b9bb2f6e0 R15: 0000000000000000
[ +0.007151] </TASK>
[ +0.002204] ---[ end trace 0000000000000000 ]---
Fix this by checking if the XDP program is being loaded or unloaded.
Then, block only loading a new program while "__I40E_IN_REMOVE" is set.
Also, move testing "__I40E_IN_REMOVE" flag to the beginning of XDP_SETUP
callback to avoid unnecessary operations and checks.
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: lantiq_etop: fix double free in detach
The number of the currently released descriptor is never incremented
which results in the same skb being released multiple times.
In the Linux kernel, the following vulnerability has been resolved:
ppp: reject claimed-as-LCP but actually malformed packets
Since 'ppp_async_encode()' assumes valid LCP packets (with code
from 1 to 7 inclusive), add 'ppp_check_packet()' to ensure that
LCP packet has an actual body beyond PPP_LCP header bytes, and
reject claimed-as-LCP but actually malformed data otherwise.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: prefer nft_chain_validate
nft_chain_validate already performs loop detection because a cycle will
result in a call stack overflow (ctx->level >= NFT_JUMP_STACK_SIZE).
It also follows maps via ->validate callback in nft_lookup, so there
appears no reason to iterate the maps again.
nf_tables_check_loops() and all its helper functions can be removed.
This improves ruleset load time significantly, from 23s down to 12s.
This also fixes a crash bug. Old loop detection code can result in
unbounded recursion:
BUG: TASK stack guard page was hit at ....
Oops: stack guard page: 0000 [#1] PREEMPT SMP KASAN
CPU: 4 PID: 1539 Comm: nft Not tainted 6.10.0-rc5+ #1
[..]
with a suitable ruleset during validation of register stores.
I can't see any actual reason to attempt to check for this from
nft_validate_register_store(), at this point the transaction is still in
progress, so we don't have a full picture of the rule graph.
For nf-next it might make sense to either remove it or make this depend
on table->validate_state in case we could catch an error earlier
(for improved error reporting to userspace).
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Fix UAF when resolving a clash
KASAN reports the following UAF:
BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
Read of size 1 at addr ffff888c07603600 by task handler130/6469
Call Trace:
<IRQ>
dump_stack_lvl+0x48/0x70
print_address_description.constprop.0+0x33/0x3d0
print_report+0xc0/0x2b0
kasan_report+0xd0/0x120
__asan_load1+0x6c/0x80
tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
tcf_ct_act+0x886/0x1350 [act_ct]
tcf_action_exec+0xf8/0x1f0
fl_classify+0x355/0x360 [cls_flower]
__tcf_classify+0x1fd/0x330
tcf_classify+0x21c/0x3c0
sch_handle_ingress.constprop.0+0x2c5/0x500
__netif_receive_skb_core.constprop.0+0xb25/0x1510
__netif_receive_skb_list_core+0x220/0x4c0
netif_receive_skb_list_internal+0x446/0x620
napi_complete_done+0x157/0x3d0
gro_cell_poll+0xcf/0x100
__napi_poll+0x65/0x310
net_rx_action+0x30c/0x5c0
__do_softirq+0x14f/0x491
__irq_exit_rcu+0x82/0xc0
irq_exit_rcu+0xe/0x20
common_interrupt+0xa1/0xb0
</IRQ>
<TASK>
asm_common_interrupt+0x27/0x40
Allocated by task 6469:
kasan_save_stack+0x38/0x70
kasan_set_track+0x25/0x40
kasan_save_alloc_info+0x1e/0x40
__kasan_krealloc+0x133/0x190
krealloc+0xaa/0x130
nf_ct_ext_add+0xed/0x230 [nf_conntrack]
tcf_ct_act+0x1095/0x1350 [act_ct]
tcf_action_exec+0xf8/0x1f0
fl_classify+0x355/0x360 [cls_flower]
__tcf_classify+0x1fd/0x330
tcf_classify+0x21c/0x3c0
sch_handle_ingress.constprop.0+0x2c5/0x500
__netif_receive_skb_core.constprop.0+0xb25/0x1510
__netif_receive_skb_list_core+0x220/0x4c0
netif_receive_skb_list_internal+0x446/0x620
napi_complete_done+0x157/0x3d0
gro_cell_poll+0xcf/0x100
__napi_poll+0x65/0x310
net_rx_action+0x30c/0x5c0
__do_softirq+0x14f/0x491
Freed by task 6469:
kasan_save_stack+0x38/0x70
kasan_set_track+0x25/0x40
kasan_save_free_info+0x2b/0x60
____kasan_slab_free+0x180/0x1f0
__kasan_slab_free+0x12/0x30
slab_free_freelist_hook+0xd2/0x1a0
__kmem_cache_free+0x1a2/0x2f0
kfree+0x78/0x120
nf_conntrack_free+0x74/0x130 [nf_conntrack]
nf_ct_destroy+0xb2/0x140 [nf_conntrack]
__nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack]
nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack]
__nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack]
tcf_ct_act+0x12ad/0x1350 [act_ct]
tcf_action_exec+0xf8/0x1f0
fl_classify+0x355/0x360 [cls_flower]
__tcf_classify+0x1fd/0x330
tcf_classify+0x21c/0x3c0
sch_handle_ingress.constprop.0+0x2c5/0x500
__netif_receive_skb_core.constprop.0+0xb25/0x1510
__netif_receive_skb_list_core+0x220/0x4c0
netif_receive_skb_list_internal+0x446/0x620
napi_complete_done+0x157/0x3d0
gro_cell_poll+0xcf/0x100
__napi_poll+0x65/0x310
net_rx_action+0x30c/0x5c0
__do_softirq+0x14f/0x491
The ct may be dropped if a clash has been resolved but is still passed to
the tcf_ct_flow_table_process_conn function for further usage. This issue
can be fixed by retrieving ct from skb again after confirming conntrack.
In the Linux kernel, the following vulnerability has been resolved:
firmware: cs_dsp: Fix overflow checking of wmfw header
Fix the checking that firmware file buffer is large enough for the
wmfw header, to prevent overrunning the buffer.
The original code tested that the firmware data buffer contained
enough bytes for the sums of the size of the structs
wmfw_header + wmfw_adsp1_sizes + wmfw_footer
But wmfw_adsp1_sizes is only used on ADSP1 firmware. For ADSP2 and
Halo Core the equivalent struct is wmfw_adsp2_sizes, which is
4 bytes longer. So the length check didn't guarantee that there
are enough bytes in the firmware buffer for a header with
wmfw_adsp2_sizes.
This patch splits the length check into three separate parts. Each
of the wmfw_header, wmfw_adsp?_sizes and wmfw_footer are checked
separately before they are used.
In the Linux kernel, the following vulnerability has been resolved:
firmware: cs_dsp: Prevent buffer overrun when processing V2 alg headers
Check that all fields of a V2 algorithm header fit into the available
firmware data buffer.
The wmfw V2 format introduced variable-length strings in the algorithm
block header. This means the overall header length is variable, and the
position of most fields varies depending on the length of the string
fields. Each field must be checked to ensure that it does not overflow
the firmware data buffer.
As this ia bugfix patch, the fixes avoid making any significant change to
the existing code. This makes it easier to review and less likely to
introduce new bugs.
In the Linux kernel, the following vulnerability has been resolved:
net: ks8851: Fix deadlock with the SPI chip variant
When SMP is enabled and spinlocks are actually functional then there is
a deadlock with the 'statelock' spinlock between ks8851_start_xmit_spi
and ks8851_irq:
watchdog: BUG: soft lockup - CPU#0 stuck for 27s!
call trace:
queued_spin_lock_slowpath+0x100/0x284
do_raw_spin_lock+0x34/0x44
ks8851_start_xmit_spi+0x30/0xb8
ks8851_start_xmit+0x14/0x20
netdev_start_xmit+0x40/0x6c
dev_hard_start_xmit+0x6c/0xbc
sch_direct_xmit+0xa4/0x22c
__qdisc_run+0x138/0x3fc
qdisc_run+0x24/0x3c
net_tx_action+0xf8/0x130
handle_softirqs+0x1ac/0x1f0
__do_softirq+0x14/0x20
____do_softirq+0x10/0x1c
call_on_irq_stack+0x3c/0x58
do_softirq_own_stack+0x1c/0x28
__irq_exit_rcu+0x54/0x9c
irq_exit_rcu+0x10/0x1c
el1_interrupt+0x38/0x50
el1h_64_irq_handler+0x18/0x24
el1h_64_irq+0x64/0x68
__netif_schedule+0x6c/0x80
netif_tx_wake_queue+0x38/0x48
ks8851_irq+0xb8/0x2c8
irq_thread_fn+0x2c/0x74
irq_thread+0x10c/0x1b0
kthread+0xc8/0xd8
ret_from_fork+0x10/0x20
This issue has not been identified earlier because tests were done on
a device with SMP disabled and so spinlocks were actually NOPs.
Now use spin_(un)lock_bh for TX queue related locking to avoid execution
of softirq work synchronously that would lead to a deadlock.
In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix duplicate endpoint bug by clearing reserved bits in the descriptor
Syzbot has identified a bug in usbcore (see the Closes: tag below)
caused by our assumption that the reserved bits in an endpoint
descriptor's bEndpointAddress field will always be 0. As a result of
the bug, the endpoint_is_duplicate() routine in config.c (and possibly
other routines as well) may believe that two descriptors are for
distinct endpoints, even though they have the same direction and
endpoint number. This can lead to confusion, including the bug
identified by syzbot (two descriptors with matching endpoint numbers
and directions, where one was interrupt and the other was bulk).
To fix the bug, we will clear the reserved bits in bEndpointAddress
when we parse the descriptor. (Note that both the USB-2.0 and USB-3.1
specs say these bits are "Reserved, reset to zero".) This requires us
to make a copy of the descriptor earlier in usb_parse_endpoint() and
use the copy instead of the original when checking for duplicates.
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix kernel bug on rename operation of broken directory
Syzbot reported that in rename directory operation on broken directory on
nilfs2, __block_write_begin_int() called to prepare block write may fail
BUG_ON check for access exceeding the folio/page size.
This is because nilfs_dotdot(), which gets parent directory reference
entry ("..") of the directory to be moved or renamed, does not check
consistency enough, and may return location exceeding folio/page size for
broken directories.
Fix this issue by checking required directory entries ("." and "..") in
the first chunk of the directory in nilfs_dotdot().
In the Linux kernel, the following vulnerability has been resolved:
cachestat: do not flush stats in recency check
syzbot detects that cachestat() is flushing stats, which can sleep, in its
RCU read section (see [1]). This is done in the workingset_test_recent()
step (which checks if the folio's eviction is recent).
Move the stat flushing step to before the RCU read section of cachestat,
and skip stat flushing during the recency check.
[1]: https://lore.kernel.org/cgroups/000000000000f71227061bdf97e0@google.com/
In the Linux kernel, the following vulnerability has been resolved:
mm: vmalloc: check if a hash-index is in cpu_possible_mask
The problem is that there are systems where cpu_possible_mask has gaps
between set CPUs, for example SPARC. In this scenario addr_to_vb_xa()
hash function can return an index which accesses to not-possible and not
setup CPU area using per_cpu() macro. This results in an oops on SPARC.
A per-cpu vmap_block_queue is also used as hash table, incorrectly
assuming the cpu_possible_mask has no gaps. Fix it by adjusting an index
to a next possible CPU.