| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Use scratch field in MMIO fragment to hold small write values
When exiting to userspace to service an emulated MMIO write, copy the
to-be-written value to a scratch field in the MMIO fragment if the size
of the data payload is 8 bytes or less, i.e. can fit in a single chunk,
instead of pointing the fragment directly at the source value.
This fixes a class of use-after-free bugs that occur when the emulator
initiates a write using an on-stack, local variable as the source, the
write splits a page boundary, *and* both pages are MMIO pages. Because
KVM's ABI only allows for physically contiguous MMIO requests, accesses
that split MMIO pages are separated into two fragments, and are sent to
userspace one at a time. When KVM attempts to complete userspace MMIO in
response to KVM_RUN after the first fragment, KVM will detect the second
fragment and generate a second userspace exit, and reference the on-stack
variable.
The issue is most visible if the second KVM_RUN is performed by a separate
task, in which case the stack of the initiating task can show up as truly
freed data.
==================================================================
BUG: KASAN: use-after-free in complete_emulated_mmio+0x305/0x420
Read of size 1 at addr ffff888009c378d1 by task syz-executor417/984
CPU: 1 PID: 984 Comm: syz-executor417 Not tainted 5.10.0-182.0.0.95.h2627.eulerosv2r13.x86_64 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Call Trace:
dump_stack+0xbe/0xfd
print_address_description.constprop.0+0x19/0x170
__kasan_report.cold+0x6c/0x84
kasan_report+0x3a/0x50
check_memory_region+0xfd/0x1f0
memcpy+0x20/0x60
complete_emulated_mmio+0x305/0x420
kvm_arch_vcpu_ioctl_run+0x63f/0x6d0
kvm_vcpu_ioctl+0x413/0xb20
__se_sys_ioctl+0x111/0x160
do_syscall_64+0x30/0x40
entry_SYSCALL_64_after_hwframe+0x67/0xd1
RIP: 0033:0x42477d
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007faa8e6890e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004d7338 RCX: 000000000042477d
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00000000004d7330 R08: 00007fff28d546df R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004d733c
R13: 0000000000000000 R14: 000000000040a200 R15: 00007fff28d54720
The buggy address belongs to the page:
page:0000000029f6a428 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9c37
flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000000 0000000000000000 ffffea0000270dc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888009c37780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888009c37800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888009c37880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888009c37900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888009c37980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
The bug can also be reproduced with a targeted KVM-Unit-Test by hacking
KVM to fill a large on-stack variable in complete_emulated_mmio(), i.e. by
overwrite the data value with garbage.
Limit the use of the scratch fields to 8-byte or smaller accesses, and to
just writes, as larger accesses and reads are not affected thanks to
implementation details in the emulator, but add a sanity check to ensure
those details don't change in the future. Specifically, KVM never uses
on-stack variables for accesses larger that 8 bytes, e.g. uses an operand
in the emulator context, and *al
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: qcom: q6apm: move component registration to unmanaged version
q6apm component registers dais dynamically from ASoC toplology, which
are allocated using device managed version apis. Allocating both
component and dynamic dais using managed version could lead to incorrect
free ordering, dai will be freed while component still holding references
to it.
Fix this issue by moving component to unmanged version so
that the dai pointers are only freeded after the component is removed.
==================================================================
BUG: KASAN: slab-use-after-free in snd_soc_del_component_unlocked+0x3d4/0x400 [snd_soc_core]
Read of size 8 at addr ffff00084493a6e8 by task kworker/u48:0/3426
Tainted: [W]=WARN
Hardware name: LENOVO 21N2ZC5PUS/21N2ZC5PUS, BIOS N42ET57W (1.31 ) 08/08/2024
Workqueue: pdr_notifier_wq pdr_notifier_work [pdr_interface]
Call trace:
show_stack+0x28/0x7c (C)
dump_stack_lvl+0x60/0x80
print_report+0x160/0x4b4
kasan_report+0xac/0xfc
__asan_report_load8_noabort+0x20/0x34
snd_soc_del_component_unlocked+0x3d4/0x400 [snd_soc_core]
snd_soc_unregister_component_by_driver+0x50/0x88 [snd_soc_core]
devm_component_release+0x30/0x5c [snd_soc_core]
devres_release_all+0x13c/0x210
device_unbind_cleanup+0x20/0x190
device_release_driver_internal+0x350/0x468
device_release_driver+0x18/0x30
bus_remove_device+0x1a0/0x35c
device_del+0x314/0x7f0
device_unregister+0x20/0xbc
apr_remove_device+0x5c/0x7c [apr]
device_for_each_child+0xd8/0x160
apr_pd_status+0x7c/0xa8 [apr]
pdr_notifier_work+0x114/0x240 [pdr_interface]
process_one_work+0x500/0xb70
worker_thread+0x630/0xfb0
kthread+0x370/0x6c0
ret_from_fork+0x10/0x20
Allocated by task 77:
kasan_save_stack+0x40/0x68
kasan_save_track+0x20/0x40
kasan_save_alloc_info+0x44/0x58
__kasan_kmalloc+0xbc/0xdc
__kmalloc_node_track_caller_noprof+0x1f4/0x620
devm_kmalloc+0x7c/0x1c8
snd_soc_register_dai+0x50/0x4f0 [snd_soc_core]
soc_tplg_pcm_elems_load+0x55c/0x1eb8 [snd_soc_core]
snd_soc_tplg_component_load+0x4f8/0xb60 [snd_soc_core]
audioreach_tplg_init+0x124/0x1fc [snd_q6apm]
q6apm_audio_probe+0x10/0x1c [snd_q6apm]
snd_soc_component_probe+0x5c/0x118 [snd_soc_core]
soc_probe_component+0x44c/0xaf0 [snd_soc_core]
snd_soc_bind_card+0xad0/0x2370 [snd_soc_core]
snd_soc_register_card+0x3b0/0x4c0 [snd_soc_core]
devm_snd_soc_register_card+0x50/0xc8 [snd_soc_core]
x1e80100_platform_probe+0x208/0x368 [snd_soc_x1e80100]
platform_probe+0xc0/0x188
really_probe+0x188/0x804
__driver_probe_device+0x158/0x358
driver_probe_device+0x60/0x190
__device_attach_driver+0x16c/0x2a8
bus_for_each_drv+0x100/0x194
__device_attach+0x174/0x380
device_initial_probe+0x14/0x20
bus_probe_device+0x124/0x154
deferred_probe_work_func+0x140/0x220
process_one_work+0x500/0xb70
worker_thread+0x630/0xfb0
kthread+0x370/0x6c0
ret_from_fork+0x10/0x20
Freed by task 3426:
kasan_save_stack+0x40/0x68
kasan_save_track+0x20/0x40
__kasan_save_free_info+0x4c/0x80
__kasan_slab_free+0x78/0xa0
kfree+0x100/0x4a4
devres_release_all+0x144/0x210
device_unbind_cleanup+0x20/0x190
device_release_driver_internal+0x350/0x468
device_release_driver+0x18/0x30
bus_remove_device+0x1a0/0x35c
device_del+0x314/0x7f0
device_unregister+0x20/0xbc
apr_remove_device+0x5c/0x7c [apr]
device_for_each_child+0xd8/0x160
apr_pd_status+0x7c/0xa8 [apr]
pdr_notifier_work+0x114/0x240 [pdr_interface]
process_one_work+0x500/0xb70
worker_thread+0x630/0xfb0
kthread+0x370/0x6c0
ret_from_fork+0x10/0x20 |
| In the Linux kernel, the following vulnerability has been resolved:
mm: blk-cgroup: fix use-after-free in cgwb_release_workfn()
cgwb_release_workfn() calls css_put(wb->blkcg_css) and then later accesses
wb->blkcg_css again via blkcg_unpin_online(). If css_put() drops the last
reference, the blkcg can be freed asynchronously (css_free_rwork_fn ->
blkcg_css_free -> kfree) before blkcg_unpin_online() dereferences the
pointer to access blkcg->online_pin, resulting in a use-after-free:
BUG: KASAN: slab-use-after-free in blkcg_unpin_online (./include/linux/instrumented.h:112 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 block/blk-cgroup.c:1367)
Write of size 4 at addr ff11000117aa6160 by task kworker/71:1/531
Workqueue: cgwb_release cgwb_release_workfn
Call Trace:
<TASK>
blkcg_unpin_online (./include/linux/instrumented.h:112 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 block/blk-cgroup.c:1367)
cgwb_release_workfn (mm/backing-dev.c:629)
process_scheduled_works (kernel/workqueue.c:3278 kernel/workqueue.c:3385)
Freed by task 1016:
kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6246 mm/slub.c:6561)
css_free_rwork_fn (kernel/cgroup/cgroup.c:5542)
process_scheduled_works (kernel/workqueue.c:3302 kernel/workqueue.c:3385)
** Stack based on commit 66672af7a095 ("Add linux-next specific files
for 20260410")
I am seeing this crash sporadically in Meta fleet across multiple kernel
versions. A full reproducer is available at:
https://github.com/leitao/debug/blob/main/reproducers/repro_blkcg_uaf.sh
(The race window is narrow. To make it easily reproducible, inject a
msleep(100) between css_put() and blkcg_unpin_online() in
cgwb_release_workfn(). With that delay and a KASAN-enabled kernel, the
reproducer triggers the splat reliably in less than a second.)
Fix this by moving blkcg_unpin_online() before css_put(), so the
cgwb's CSS reference keeps the blkcg alive while blkcg_unpin_online()
accesses it. |
| In the Linux kernel, the following vulnerability has been resolved:
can: raw: fix ro->uniq use-after-free in raw_rcv()
raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro->uniq, leading to a use-after-free of the
percpu uniq storage.
Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.
[mkl: applied manually] |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Do not skip unrelated mode changes in DSC validation
Starting with commit 17ce8a6907f7 ("drm/amd/display: Add dsc pre-validation in
atomic check"), amdgpu resets the CRTC state mode_changed flag to false when
recomputing the DSC configuration results in no timing change for a particular
stream.
However, this is incorrect in scenarios where a change in MST/DSC configuration
happens in the same KMS commit as another (unrelated) mode change. For example,
the integrated panel of a laptop may be configured differently (e.g., HDR
enabled/disabled) depending on whether external screens are attached. In this
case, plugging in external DP-MST screens may result in the mode_changed flag
being dropped incorrectly for the integrated panel if its DSC configuration
did not change during precomputation in pre_validate_dsc().
At this point, however, dm_update_crtc_state() has already created new streams
for CRTCs with DSC-independent mode changes. In turn,
amdgpu_dm_commit_streams() will never release the old stream, resulting in a
memory leak. amdgpu_dm_atomic_commit_tail() will never acquire a reference to
the new stream either, which manifests as a use-after-free when the stream gets
disabled later on:
BUG: KASAN: use-after-free in dc_stream_release+0x25/0x90 [amdgpu]
Write of size 4 at addr ffff88813d836524 by task kworker/9:9/29977
Workqueue: events drm_mode_rmfb_work_fn
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0xa0
print_address_description.constprop.0+0x88/0x320
? dc_stream_release+0x25/0x90 [amdgpu]
print_report+0xfc/0x1ff
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x225/0x4e0
? dc_stream_release+0x25/0x90 [amdgpu]
kasan_report+0xe1/0x180
? dc_stream_release+0x25/0x90 [amdgpu]
kasan_check_range+0x125/0x200
dc_stream_release+0x25/0x90 [amdgpu]
dc_state_destruct+0x14d/0x5c0 [amdgpu]
dc_state_release.part.0+0x4e/0x130 [amdgpu]
dm_atomic_destroy_state+0x3f/0x70 [amdgpu]
drm_atomic_state_default_clear+0x8ee/0xf30
? drm_mode_object_put.part.0+0xb1/0x130
__drm_atomic_state_free+0x15c/0x2d0
atomic_remove_fb+0x67e/0x980
Since there is no reliable way of figuring out whether a CRTC has unrelated
mode changes pending at the time of DSC validation, remember the value of the
mode_changed flag from before the point where a CRTC was marked as potentially
affected by a change in DSC configuration. Reset the mode_changed flag to this
earlier value instead in pre_validate_dsc().
(cherry picked from commit cc7c7121ae082b7b82891baa7280f1ff2608f22b) |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: do not expire session on binding failure
When a multichannel session binding request fails (e.g. wrong password),
the error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED.
However, during binding, sess points to the target session looked up via
ksmbd_session_lookup_slowpath() -- which belongs to another connection's
user. This allows a remote attacker to invalidate any active session by
simply sending a binding request with a wrong password (DoS).
Fix this by skipping session expiration when the failed request was
a binding attempt, since the session does not belong to the current
connection. The reference taken by ksmbd_session_lookup_slowpath() is
still correctly released via ksmbd_user_session_put(). |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: unset conn->binding on failed binding request
When a multichannel SMB2_SESSION_SETUP request with
SMB2_SESSION_REQ_FLAG_BINDING fails ksmbd sets conn->binding = true
but never clears it on the error path. This leaves the connection in
a binding state where all subsequent ksmbd_session_lookup_all() calls
fall back to the global sessions table. This fix it by clearing
conn->binding = false in the error path. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: add missing netlink policy validations
Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.
These attributes are used by the kernel without any validation.
Extend the netlink policies accordingly.
Quoting the reporter:
nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE
value directly to ct->proto.sctp.state without checking that it is
within the valid range. [..]
and: ... with exp->dir = 100, the access at
ct->master->tuplehash[100] reads 5600 bytes past the start of a
320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by
UBSAN. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure
ieee80211_tx_prepare_skb() has three error paths, but only two of them
free the skb. The first error path (ieee80211_tx_prepare() returning
TX_DROP) does not free it, while invoke_tx_handlers() failure and the
fragmentation check both do.
Add kfree_skb() to the first error path so all three are consistent,
and remove the now-redundant frees in callers (ath9k, mt76,
mac80211_hwsim) to avoid double-free.
Document the skb ownership guarantee in the function's kdoc. |
| In the Linux kernel, the following vulnerability has been resolved:
af_unix: Give up GC if MSG_PEEK intervened.
Igor Ushakov reported that GC purged the receive queue of
an alive socket due to a race with MSG_PEEK with a nice repro.
This is the exact same issue previously fixed by commit
cbcf01128d0a ("af_unix: fix garbage collect vs MSG_PEEK").
After GC was replaced with the current algorithm, the cited
commit removed the locking dance in unix_peek_fds() and
reintroduced the same issue.
The problem is that MSG_PEEK bumps a file refcount without
interacting with GC.
Consider an SCC containing sk-A and sk-B, where sk-A is
close()d but can be recv()ed via sk-B.
The bad thing happens if sk-A is recv()ed with MSG_PEEK from
sk-B and sk-B is close()d while GC is checking unix_vertex_dead()
for sk-A and sk-B.
GC thread User thread
--------- -----------
unix_vertex_dead(sk-A)
-> true <------.
\
`------ recv(sk-B, MSG_PEEK)
invalidate !! -> sk-A's file refcount : 1 -> 2
close(sk-B)
-> sk-B's file refcount : 2 -> 1
unix_vertex_dead(sk-B)
-> true
Initially, sk-A's file refcount is 1 by the inflight fd in sk-B
recvq. GC thinks sk-A is dead because the file refcount is the
same as the number of its inflight fds.
However, sk-A's file refcount is bumped silently by MSG_PEEK,
which invalidates the previous evaluation.
At this moment, sk-B's file refcount is 2; one by the open fd,
and one by the inflight fd in sk-A. The subsequent close()
releases one refcount by the former.
Finally, GC incorrectly concludes that both sk-A and sk-B are dead.
One option is to restore the locking dance in unix_peek_fds(),
but we can resolve this more elegantly thanks to the new algorithm.
The point is that the issue does not occur without the subsequent
close() and we actually do not need to synchronise MSG_PEEK with
the dead SCC detection.
When the issue occurs, close() and GC touch the same file refcount.
If GC sees the refcount being decremented by close(), it can just
give up garbage-collecting the SCC.
Therefore, we only need to signal the race during MSG_PEEK with
a proper memory barrier to make it visible to the GC.
Let's use seqcount_t to notify GC when MSG_PEEK occurs and let
it defer the SCC to the next run.
This way no locking is needed on the MSG_PEEK side, and we can
avoid imposing a penalty on every MSG_PEEK unnecessarily.
Note that we can retry within unix_scc_dead() if MSG_PEEK is
detected, but we do not do so to avoid hung task splat from
abusive MSG_PEEK calls. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: send: check for inline extents in range_is_hole_in_parent()
Before accessing the disk_bytenr field of a file extent item we need
to check if we are dealing with an inline extent.
This is because for inline extents their data starts at the offset of
the disk_bytenr field. So accessing the disk_bytenr
means we are accessing inline data or in case the inline data is less
than 8 bytes we can actually cause an invalid
memory access if this inline extent item is the first item in the leaf
or access metadata from other items. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix recvmsg() unconditional requeue
If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at
the front of the recvmsg queue already has its mutex locked, it requeues
the call - whether or not the call is already queued. The call may be on
the queue because MSG_PEEK was also passed and so the call was not dequeued
or because the I/O thread requeued it.
The unconditional requeue may then corrupt the recvmsg queue, leading to
things like UAFs or refcount underruns.
Fix this by only requeuing the call if it isn't already on the queue - and
moving it to the front if it is already queued. If we don't queue it, we
have to put the ref we obtained by dequeuing it.
Also, MSG_PEEK doesn't dequeue the call so shouldn't call
rxrpc_notify_socket() for the call if we didn't use up all the data on the
queue, so fix that also. |
| In the Linux kernel, the following vulnerability has been resolved:
ublk: fix deadlock when reading partition table
When one process(such as udev) opens ublk block device (e.g., to read
the partition table via bdev_open()), a deadlock[1] can occur:
1. bdev_open() grabs disk->open_mutex
2. The process issues read I/O to ublk backend to read partition table
3. In __ublk_complete_rq(), blk_update_request() or blk_mq_end_request()
runs bio->bi_end_io() callbacks
4. If this triggers fput() on file descriptor of ublk block device, the
work may be deferred to current task's task work (see fput() implementation)
5. This eventually calls blkdev_release() from the same context
6. blkdev_release() tries to grab disk->open_mutex again
7. Deadlock: same task waiting for a mutex it already holds
The fix is to run blk_update_request() and blk_mq_end_request() with bottom
halves disabled. This forces blkdev_release() to run in kernel work-queue
context instead of current task work context, and allows ublk server to make
forward progress, and avoids the deadlock.
[axboe: rewrite comment in ublk] |
| In the Linux kernel, the following vulnerability has been resolved:
can: gs_usb: gs_usb_xmit_callback(): fix handling of failed transmitted URBs
The driver lacks the cleanup of failed transfers of URBs. This reduces the
number of available URBs per error by 1. This leads to reduced performance
and ultimately to a complete stop of the transmission.
If the sending of a bulk URB fails do proper cleanup:
- increase netdev stats
- mark the echo_sbk as free
- free the driver's context and do accounting
- wake the send queue |
| In the Linux kernel, the following vulnerability has been resolved:
binfmt_misc: restore write access before closing files opened by open_exec()
bm_register_write() opens an executable file using open_exec(), which
internally calls do_open_execat() and denies write access on the file to
avoid modification while it is being executed.
However, when an error occurs, bm_register_write() closes the file using
filp_close() directly. This does not restore the write permission, which
may cause subsequent write operations on the same file to fail.
Fix this by calling exe_file_allow_write_access() before filp_close() to
restore the write permission properly. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: remove two invalid BUG_ON()s
Those can be triggered trivially by userspace. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic
The decompress_io_ctx may be released asynchronously after
I/O completion. If this file is deleted immediately after read,
and the kworker of processing post_read_wq has not been executed yet
due to high workloads, It is possible that the inode(f2fs_inode_info)
is evicted and freed before it is used f2fs_free_dic.
The UAF case as below:
Thread A Thread B
- f2fs_decompress_end_io
- f2fs_put_dic
- queue_work
add free_dic work to post_read_wq
- do_unlink
- iput
- evict
- call_rcu
This file is deleted after read.
Thread C kworker to process post_read_wq
- rcu_do_batch
- f2fs_free_inode
- kmem_cache_free
inode is freed by rcu
- process_scheduled_works
- f2fs_late_free_dic
- f2fs_free_dic
- f2fs_release_decomp_mem
read (dic->inode)->i_compress_algorithm
This patch store compress_algorithm and sbi in dic to avoid inode UAF.
In addition, the previous solution is deprecated in [1] may cause system hang.
[1] https://lore.kernel.org/all/c36ab955-c8db-4a8b-a9d0-f07b5f426c3f@kernel.org |
| In the Linux kernel, the following vulnerability has been resolved:
riscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler
Naresh Kamboju reported a "Bad frame pointer" kernel warning while
running LTP trace ftrace_stress_test.sh in riscv. We can reproduce the
same issue with the following command:
```
$ cd /sys/kernel/debug/tracing
$ echo 'f:myprobe do_nanosleep%return args1=$retval' > dynamic_events
$ echo 1 > events/fprobes/enable
$ echo 1 > tracing_on
$ sleep 1
```
And we can get the following kernel warning:
[ 127.692888] ------------[ cut here ]------------
[ 127.693755] Bad frame pointer: expected ff2000000065be50, received ba34c141e9594000
[ 127.693755] from func do_nanosleep return to ffffffff800ccb16
[ 127.698699] WARNING: CPU: 1 PID: 129 at kernel/trace/fgraph.c:755 ftrace_return_to_handler+0x1b2/0x1be
[ 127.699894] Modules linked in:
[ 127.700908] CPU: 1 UID: 0 PID: 129 Comm: sleep Not tainted 6.14.0-rc3-g0ab191c74642 #32
[ 127.701453] Hardware name: riscv-virtio,qemu (DT)
[ 127.701859] epc : ftrace_return_to_handler+0x1b2/0x1be
[ 127.702032] ra : ftrace_return_to_handler+0x1b2/0x1be
[ 127.702151] epc : ffffffff8013b5e0 ra : ffffffff8013b5e0 sp : ff2000000065bd10
[ 127.702221] gp : ffffffff819c12f8 tp : ff60000080853100 t0 : 6e00000000000000
[ 127.702284] t1 : 0000000000000020 t2 : 6e7566206d6f7266 s0 : ff2000000065bd80
[ 127.702346] s1 : ff60000081262000 a0 : 000000000000007b a1 : ffffffff81894f20
[ 127.702408] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : 0000000000000000
[ 127.702470] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038
[ 127.702530] s2 : ba34c141e9594000 s3 : 0000000000000000 s4 : ff2000000065bdd0
[ 127.702591] s5 : 00007fff8adcf400 s6 : 000055556dc1d8c0 s7 : 0000000000000068
[ 127.702651] s8 : 00007fff8adf5d10 s9 : 000000000000006d s10: 0000000000000001
[ 127.702710] s11: 00005555737377c8 t3 : ffffffff819d899e t4 : ffffffff819d899e
[ 127.702769] t5 : ffffffff819d89a0 t6 : ff2000000065bb18
[ 127.702826] status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003
[ 127.703292] [<ffffffff8013b5e0>] ftrace_return_to_handler+0x1b2/0x1be
[ 127.703760] [<ffffffff80017bce>] return_to_handler+0x16/0x26
[ 127.704009] [<ffffffff80017bb8>] return_to_handler+0x0/0x26
[ 127.704057] [<ffffffff800d3352>] common_nsleep+0x42/0x54
[ 127.704117] [<ffffffff800d44a2>] __riscv_sys_clock_nanosleep+0xba/0x10a
[ 127.704176] [<ffffffff80901c56>] do_trap_ecall_u+0x188/0x218
[ 127.704295] [<ffffffff8090cc3e>] handle_exception+0x14a/0x156
[ 127.705436] ---[ end trace 0000000000000000 ]---
The reason is that the stack layout for constructing argument for the
ftrace_return_to_handler in the return_to_handler does not match the
__arch_ftrace_regs structure of riscv, leading to unexpected results. |
| In the Linux kernel, the following vulnerability has been resolved:
dlm: fix possible lkb_resource null dereference
This patch fixes a possible null pointer dereference when this function is
called from request_lock() as lkb->lkb_resource is not assigned yet,
only after validate_lock_args() by calling attach_lkb(). Another issue
is that a resource name could be a non printable bytearray and we cannot
assume to be ASCII coded.
The log functionality is probably never being hit when DLM is used in
normal way and no debug logging is enabled. The null pointer dereference
can only occur on a new created lkb that does not have the resource
assigned yet, it probably never hits the null pointer dereference but we
should be sure that other changes might not change this behaviour and we
actually can hit the mentioned null pointer dereference.
In this patch we just drop the printout of the resource name, the lkb id
is enough to make a possible connection to a resource name if this
exists. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser()
When the buffer length of the recvmsg system call is 0, we got the
flollowing soft lockup problem:
watchdog: BUG: soft lockup - CPU#3 stuck for 27s! [a.out:6149]
CPU: 3 PID: 6149 Comm: a.out Kdump: loaded Not tainted 6.2.0+ #30
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:remove_wait_queue+0xb/0xc0
Code: 5e 41 5f c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 57 <41> 56 41 55 41 54 55 48 89 fd 53 48 89 f3 4c 8d 6b 18 4c 8d 73 20
RSP: 0018:ffff88811b5978b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88811a7d3780 RCX: ffffffffb7a4d768
RDX: dffffc0000000000 RSI: ffff88811b597908 RDI: ffff888115408040
RBP: 1ffff110236b2f1b R08: 0000000000000000 R09: ffff88811a7d37e7
R10: ffffed10234fa6fc R11: 0000000000000001 R12: ffff88811179b800
R13: 0000000000000001 R14: ffff88811a7d38a8 R15: ffff88811a7d37e0
FS: 00007f6fb5398740(0000) GS:ffff888237180000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000010b6ba002 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tcp_msg_wait_data+0x279/0x2f0
tcp_bpf_recvmsg_parser+0x3c6/0x490
inet_recvmsg+0x280/0x290
sock_recvmsg+0xfc/0x120
____sys_recvmsg+0x160/0x3d0
___sys_recvmsg+0xf0/0x180
__sys_recvmsg+0xea/0x1a0
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
The logic in tcp_bpf_recvmsg_parser is as follows:
msg_bytes_ready:
copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
if (!copied) {
wait data;
goto msg_bytes_ready;
}
In this case, "copied" always is 0, the infinite loop occurs.
According to the Linux system call man page, 0 should be returned in this
case. Therefore, in tcp_bpf_recvmsg_parser(), if the length is 0, directly
return. Also modify several other functions with the same problem. |
