| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix use-after-free in smc_rx_pipe_buf_release()
smc_rx_splice() hands RMB pages to a pipe and takes a socket reference
per entry so the smc_sock stays alive until the reader finishes. The
connection does not: a concurrent close runs smc_conn_free(), which
releases the receive buffer back to the link group pool.
smc_rx_pipe_buf_release() tests sk_state before taking the socket lock.
The state can change between the test and the lock, and
smc_rx_update_cons() then dereferences conn->rmb_desc and walks
conn->lgr, which smc_conn_free() has already released. On the
is_reg_err path smcr_buf_unuse() frees the descriptor outright, so
this is a use-after-free.
Take the socket lock first and test conn->freed instead.
smc_conn_free() sets that flag before releasing anything, and every
caller holds the socket lock. The two paths exclude each other: either
the pipe release runs first with everything valid, or it sees the flag
and skips the update. |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: unregister the connection before draining the rx tasklet
smc_conn_free() calls smc_ism_unset_conn() only while the link group is
still on its device list, and never sets conn->killed.
smc_lgr_terminate_sched() unlinks the group immediately and defers killing
its connections to a work item, so a connection freed in that window keeps
its smcd->conn[] slot with both gates in smcd_handle_irq() open, and the
device can re-arm the receive tasklet after tasklet_kill() has returned. On
the DMB-nocopy path the ghost send buffer is freed right after that drain,
so the re-armed tasklet dereferences it.
Unregister unconditionally and drain before the detach at both teardown
sites, mirroring rmb_desc, which smc_buf_unuse() releases after the drain.
Clear conn->sndbuf_desc before freeing it as well, so a reader that samples
the pointer cannot get one that is already freed. |
| In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: don't touch shared zerocopy state in skb_tx_error()
skb_tx_error() completes the zerocopy uarg and clears
SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears
SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone
shares, while the caller only owns the reference it is about to drop.
Through a clone it tells the producer its pages are free and drops
SKBFL_SHARED_FRAG for an skb that is still in flight.
Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC:
clone_execute() sends a skb_clone() into ovs_dp_process_packet() while
do_execute_actions() keeps forwarding the original, and skb_clone()
does not privatise the frags here -- skb_orphan_frags() returns early
on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker
from the packet still being forwarded, and a later local ESP delivery
decrypts in place over frags it does not own privately.
Skip it for a cloned skb. Nothing is lost: skb_release_data() clears
the zerocopy state once the last reference to the shared data goes. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: bcd2000: clear the URB pointers on disconnect
bcd2000_free_usb_related_resources() frees both URBs and leaves the
pointers behind:
usb_kill_urb(bcd2k->midi_out_urb);
usb_kill_urb(bcd2k->midi_in_urb);
usb_free_urb(bcd2k->midi_out_urb);
usb_free_urb(bcd2k->midi_in_urb);
The rawmidi device outlives that call. A substream that is still open
when the device is unplugged reaches bcd2000_midi_send() from the
trigger path on close. That function writes to the freed URB and then
hands it to the USB core:
bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
...
ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
usb_kill_urb() does not stop a later submission either, so a submit that
races the disconnect can requeue the URB after it has been reaped.
midi_in_urb is exposed the same way: bcd2000_input_complete() resubmits
it from the completion handler.
KASAN on 7.2.0-rc5 (arm64):
BUG: KASAN: slab-use-after-free in bcd2000_midi_send [snd_bcd2000]
Write of size 4 at addr ffff00001827d388 by task bpoc/168
__asan_store4
bcd2000_midi_send [snd_bcd2000]
bcd2000_midi_output_trigger [snd_bcd2000]
snd_rawmidi_kernel_write1
close_substream.part.0
Freed by task 168:
usb_free_urb
bcd2000_disconnect [snd_bcd2000]
BUG: KASAN: slab-use-after-free in usb_submit_urb
Read of size 8 at addr ffff00001827d3b8 by task bpoc/168
Clear both pointers after freeing and test them on the paths that can
still run. Poison the URBs before freeing them: usb_poison_urb() waits
for a running completion handler and rejects any later submission, so
after it returns the input path is quiesced and only the rawmidi trigger
path can still reach bcd2000_midi_send(). No unpoison is needed; the
URBs are freed on the next line.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
i3c: master: Fix info leak and UAF in device unregister path
i3c_master_unregister_i3c_devs() clears i3cdev->dev->desc before
calling device_unregister(). During device_unregister(),
device_del() emits a KOBJ_REMOVE uevent and unbinds the driver while
the device descriptor is still expected to be valid. As a result,
i3c_device_uevent() and a racing modalias_show() can observe a NULL
desc and fall back to an uninitialized stack struct i3c_device_info,
leaking kernel stack contents in the generated modalias. Driver
.remove() callbacks may also encounter an unexpected NULL desc during
unbind.
Keep desc valid until device_unregister() has completed. Since
device_unregister() drops the device reference and may free the device,
take an extra reference with get_device() before unregistering. Clear
desc afterwards and release the extra reference with put_device().
This preserves the release-time invariant that desc must be NULL while
avoiding both the information leak and a potential use-after-free from
writing desc after the device has been released. |
| In the Linux kernel, the following vulnerability has been resolved:
smack: fix cred UAF in smack_file_send_sigiotask()
When inspecting the credentials of another task, objective credentials
(->real_cred, accessed with __task_cred()) must always be used.
Accessing ->cred on a non-current task is forbidden unless that task is
being created or destroyed; a task is allowed to change its own ->cred
pointer with no synchronization, and changing ->cred should only affect the
current syscall.
smack_file_send_sigiotask() was accessing both sets of credentials: First
tsk->cred, then __task_cred(tsk).
Fix it, always access the objective credentials here.
I have tested that this bug can lead to a KASAN-reported UAF of struct cred
in smack_file_send_sigiotask(), and that this fix prevents the race. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: make nft_object rhltable per table
The nft_object rhltable is global, this allows for accessing objects
that are being dismangled from lookup path by other existing netns.
Given the nft_obj_destroy() releases the object inmediately, this might
lead to use-after-free of these objects that are being released.
Make the existing rhltable per table to address this issue to deal with
with the nft_rcv_nl_event() path too.
Update nft_obj_lookup() to take the table as non-const, otherwise,
compiler complains when passing the objname_ht to rhltable_lookup(). |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst
The br_netfilter fake rtable is embedded in struct net_bridge and is
attached to bridged packets with skb_dst_set_noref(). If such a packet is
queued to NFQUEUE, __nf_queue() upgrades that fake dst with
skb_dst_force().
At that point the queued skb can hold a real dst reference after bridge
teardown has started. The problem is not that every bridged packet needs
its own dst reference. The problem is that NFQUEUE can keep the bridge
private fake dst alive after unregister begins.
Fix this by keeping the bridge fake dst model unchanged and pinning the
bridge master device only while the packet sits in NFQUEUE. Record the
bridge device in nf_queue_entry when the queued skb carries a bridge fake
dst, take a device reference for the queue lifetime, and drop it when the
queue entry is freed.
Also make sure queued entries are reaped when that bridge device goes
down, and drop the redundant nf_bridge_info_exists() test from the fake
dst detection.
This keeps netdev_priv(br->dev) alive until verdict completion, so the
embedded fake rtable and its metrics backing storage cannot be freed out
from under dst_release(). It also avoids the constant refcount bump and
avoids using ipv4-specific dst helpers for IPv6 bridge traffic. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: xsk: Fix unlocked writing to ICOSQ
During napi poll, when the affinity changes and there's still XSK work
to be done, we trigger an ICOSQ interrupt on the new CPU. However, this
triggering on the ICOSQ is done unprotected.
There are 2 such races:
A) mlx5e_trigger_irq() is called while mlx5e_xsk_alloc_rx_mpwqe() is
running from a different CPU due to affinity change. This can happen
because IRQ triggering is done after napi_complete_done(). At this point
the NAPI can be scheduled on a different CPU. Like this:
CPU A (old affinity, NAPI tail) CPU B (new affinity, fresh NAPI)
------------------------------- --------------------------------
napi_complete_done() clears SCHED
mlx5e_cq_arm(...)
napi_schedule_prep() sets SCHED
mlx5e_napi_poll()
mlx5e_xsk_alloc_rx_mpwqe()
mlx5e_icosq_sync_lock() // noop
memcpy 640 B UMR body
advance sq->pc by 10
mlx5e_trigger_irq(&c->icosq)
wqe_info[pi] = {NOP, 1}
mlx5e_post_nop() advances sq->pc
B) mlx5e_trigger_irq() is called on the ICOSQ when
mlx5e_trigger_napi_icosq() is running.
The obvious fix would be to lock the ICOSQ. But ICOSQ has an optimized
locking scheme that doesn't work for this scenario. Kick the async ICOSQ
instead which is always locked.
This issue was noticed in the wild with the following splat:
netdevice: ge-0-0-1: Bad OP in ICOSQ CQE: 0xd
WARNING: drivers/net/ethernet/mellanox/mlx5/core/en_rx.c:826 [...]
[...]
Call Trace:
<IRQ>
mlx5e_napi_poll+0x11d/0x7f0 [mlx5_core]
__napi_poll+0x30/0x200
? skb_defer_free_flush+0x9c/0xc0
net_rx_action+0x2fe/0x3f0
handle_softirqs+0xd8/0x340
__irq_exit_rcu+0xbc/0xe0
common_interrupt+0x85/0xa0
</IRQ>
<TASK>
asm_common_interrupt+0x26/0x40
[...]
---[ end trace 0000000000000000 ]---
mlx5_core 0000:08:00.0 ge-0-0-1: Error cqe on cqn 0x548, ci 0x2022, qn 0x8f4,
opcode 0xd, syndrome 0x2, vendor syndrome 0x68
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 01 00 68 02 01 00 08 f4 de 14 59 d2
WQE DUMP: WQ size 16384 WQ cur size 0, WQE index 0x1e14, len: 64
00000000: 00 00 00 01 d9 ed 80 02 00 00 00 01 d9 ed 90 02
00000010: 00 00 00 01 d9 ed a0 02 00 00 00 01 d9 ed b0 02
00000020: 00 00 00 01 d9 ed c0 02 00 00 00 01 d9 ed d0 02
00000030: 00 00 00 01 d9 ed e0 02 00 00 00 01 d9 ed f0 02
mlx5_core 0000:08:00.0 ge-0-0-1: Error cqe on cqn 0x548, ci 0x2023, qn 0x8f4,
opcode 0xd, syndrome 0x5, vendor syndrome 0xf9
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 01 00 f9 05 01 00 08 f4 de 15 cf d2 |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix durable reconnect error path file lifetime
After a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes
the same ksmbd_file into the session volatile-id table. If smb2_open()
then takes a later error path, cleanup first calls ksmbd_fd_put(work, fp)
and then unconditionally calls ksmbd_put_durable_fd(dh_info.fp).
In this case fp and dh_info.fp are the same object. The first put drops the
reconnect lookup reference, but the final durable put can run
__ksmbd_close_fd(NULL, fp). Because the final close is not session-aware,
it can free the file object without removing the volatile-id entry that was
just published into the session table.
Use the session-aware put for the final reconnect drop when the reconnect
had already succeeded and the error path is cleaning up the republished
file. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep
using the durable-only put path. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_counter: serialize reset with spinlock
Add a global static spinlock to serialize counter fetch+reset
operations, preventing concurrent dump-and-reset from underrunning
values.
The lock is taken before fetching the total so that two parallel
resets cannot both read the same counter values and then both
subtract them.
A global lock is used for simplicity since resets are infrequent.
If this becomes a bottleneck, it can be replaced with a per-net
lock later. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: fix potential race in tcp_v6_syn_recv_sock()
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.
After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.
Since newinet->pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.
Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.
This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context. |
| In the Linux kernel, the following vulnerability has been resolved:
clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path
When cpuhp_setup_state fails after pit_clockevent_per_cpu_init has
successfully called request_irq, the error handling jumps directly to
out_pit_clocksource_unregister without freeing the registered IRQ.
This leaks the IRQ line and, since kfree(pit) follows, leaves a
dangling pointer registered as the interrupt handler's dev_id,
potentially leading to a use-after-free if the IRQ fires afterwards.
Fix it by calling pit_clockevent_per_cpu_exit to properly release the
IRQ before falling through to the existing cleanup chain. |
| In the Linux kernel, the following vulnerability has been resolved:
rust: devres: fix race between concurrent revokers
There is a potential race condition when two paths try to revoke a
Devres concurrently.
The driver core's devres_release_all() calls Revocable::revoke() via the
release callback, while Devres::drop() calls revoke_nosync() on another
CPU.
The revoker that does not claim the is_available swap returns
immediately, but the revoker that did may still be executing
drop_in_place() on the inner data. This can cause a use-after-free when
the other revoker's caller proceeds to drop adjacent resources that
drop_in_place() still references (e.g., Devres<DmaMappedSgt> racing with
SGTable freeing the backing sg_table and pages).
Fix this by adding a Completion. The release callback signals the
Completion after revoke() finishes, and Devres::drop() waits for it when
it loses the is_available swap. This ensures the wrapped object is fully
torn down before Devres::drop() returns. |
| In the Linux kernel, the following vulnerability has been resolved:
KEYS: trusted: Fix TPM teardown ordering
trusted_tpm_exit() drops the TPM chip reference and frees the digest
array before unregistering the trusted key type. key_type_lookup()
holds key_types_sem for reading until the key operation finishes, while
unregister_key_type() takes it for writing. It therefore provides the
synchronization point that must precede backend teardown.
The current order permits this interleaving:
CPU 0 CPU 1
trusted_tpm_exit() key_type_lookup("trusted")
put_device(&chip->dev) trusted_tpm_seal()
kfree(digests) pcrlock()
unregister_key_type() tpm_pcr_extend(..., digests)
CPU 1 can consequently dereference the freed digest array. The chip can
also be released before callbacks stop using it.
KASAN reported:
BUG: KASAN: slab-use-after-free in tpm_pcr_extend+0x1f0/0x200
Read of size 2 at addr ffff88810872d000 by task poc/89
Call Trace:
tpm_pcr_extend+0x1f0/0x200
pcrlock+0x42/0x70 [trusted]
trusted_tpm_seal+0x1b6/0x570 [trusted]
trusted_instantiate+0x293/0x340 [trusted]
__key_instantiate_and_link+0xb2/0x2b0
__key_create_or_update+0x61e/0xb50
__do_sys_add_key+0x1b8/0x310
Allocated by task 88:
__kmalloc_noprof+0x1a7/0x490
do_one_initcall+0xa1/0x390
do_init_module+0x2df/0x840
Freed by task 90:
kfree+0x131/0x3c0
trusted_tpm_exit+0x59/0xa0 [trusted]
__do_sys_delete_module+0x346/0x510
Move unregister_key_type() before releasing either resource. This stops
new lookups and waits for in-flight key operations to finish before the
backend state is destroyed. |
| In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix cred UAF caused by begin_current_label_crit_section()
AppArmor's begin_current_label_crit_section() is a scary function called
from lots of LSM hooks (in particular VFS/socket-related ones) that checks
if the label referenced by the current creds is marked FLAG_STALE, and if
so, attempts to use aa_replace_current_label() to replace the creds with an
updated version that uses a new label.
The first problem with this is that it would directly lead to UAF of
`struct cred` if anything in the kernel takes a pointer to the current
creds and accesses these past a security hook invocation that replaces
creds, like so:
```
const struct cred *cred = current_cred();
alloc_file_pseudo(...);
uid_t uid = cred->euid;
```
I don't know if anything in the kernel actually does this, but I think it
is very surprising that this pattern could lead to UAF.
The second problem is that things go wrong when aa_replace_current_label()
runs with overridden credentials. aa_replace_current_label() bails out if
`current_cred() != current_real_cred()` (mirroring the check in
proc_pid_attr_write()), but this check can't actually reliably detect
overridden credentials because the overridden creds can be the same as the
objective creds.
So in approximately the following scenario, things go wrong:
1. task begins with <creds A> (as both objective and subjective creds),
with refcount=2
2. task grabs an extra reference on <creds A> for overriding
3. task calls override_creds(<creds A>), which returns a pointer to the old
subjective creds (<creds A>)
4. task enters AppArmor LSM hook
5. AppArmor checks that objective/subjective creds are equal
6. AppArmor replaces both cred pointers with <creds B> and drops 2 refs on
<creds A>
7. task leaves AppArmor LSM hook
8. task calls revert_creds(<creds A>)
9. now task->cred is <creds A> while task->real_cred is <creds B>, but the
task_struct logically holds two references to <creds B>
10. another task drops the extra reference on <creds A> that was used for
overriding, refcount drops to 0
11. now task->real_cred points to freed creds
At this point, any access to current_cred() will be UAF.
I have a test case where I run aa-disable on a profile while a process
using that profile is blocked on splice() from a FUSE passthrough file into
a full pipe; after the profile update, the pipe becomes empty, splice()
resumes, the credentials go out of sync, and a subsequent getuid() syscall
results in a KASAN UAF splat.
To fix this, instead of directly replacing creds, do it via task_work that
will run at the end of the current syscall. (The point in time at which the
cred replacement happens should have no correctness impact; it is just a
performance optimization to avoid unnecessarily touching the refcount of
the new label.)
Note that AppArmor still performs direct cred replacements in the
sb_pivotroot LSM hook after this change, and that direct cred replacements
can still happen in VFS ->write() callbacks via proc_pid_attr_write().
There are two options for what to do with aa_dup_task_ctx(): Either
explicitly reset new->label_replacement_pending after the entire
aa_task_ctx has been copied, or switch to manually copying members over.
I am switching to manually copying members over because that should make
bugs more obvious. |
| In the Linux kernel, the following vulnerability has been resolved:
mm, swap: don't free a hibernation slot that is in the swap cache
A slot with a folio in the swap cache is freed when the folio leaves the
cache, not when its count drops. swap_put_entries_cluster() follows that
rule. swap_free_hibernation_slot() does not, it calls
__swap_cluster_free_entries() whether or not a folio sits on the slot.
Cluster readahead can put one there. It walks a raw page_cluster sized
window of offsets around the faulting entry, and a hibernation slot passes
__swap_cache_add_check() because it is not a folio and its count is not
zero. Freeing the slot then clears the entry under that folio.
The folio is now unreachable from the swap table, and the offset goes back
to the allocator. The folio is still on the LRU though, so reclaim can
pick it up later. It then takes the old offset out of folio->swap and
overwrites the table entry there, which by then may belong to someone
else.
This bug can trigger silent memory corruption, process crashes, or data
instability across completely unrelated userspace applications - typically
occurring when uswsusp is preparing the hibernation image.
I found this while working on giving hibernation slots their own marker in
the swap table, which I had discussed with Kairui.
(https://lore.kernel.org/linux-mm/abp7aDgYLrxF3Me8@KASONG-MC4/) As far as
I know there are no reports, so there is no Reported-by/Closes to add.
Check for a cached folio before freeing. The slot is then left in the
ordinary state where only the swap cache holds it, and it is freed when
the folio leaves the cache, either through the reclaim below or through
normal reclaim later. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/mempolicy: skip non-present PMDs when queueing folios
Patch series "mm: handle device-private PMDs in walk callbacks", v3.
Since commit 368076f52ebe ("mm/huge_memory: add device-private THP support
to PMD operations") a PMD may hold a device-private swap entry whenever an
HMM-based GPU driver migrates an anonymous THP folio to device memory via
migrate_vma_pages().
pmd_trans_huge_lock() succeeds for such PMDs (pmd_is_huge() returns true
for any non-present, non-none huge PMD), so several MM walk callbacks that
used to assume present THP or migration entry are now reachable with a
device-private PMD. The results range from a VM_BUG_ON() firing on debug
kernels, to an oops on a bogus vmemmap dereference, to silently isolating
an unrelated live folio from LRU in the aliasing case.
This patch (of 3):
queue_folios_pmd() is called under pmd_trans_huge_lock(), whose
pmd_is_huge() check returns true for any non-present, non-none PMD
softleaf. Passing such a PMD to pmd_folio() treats the softleaf encoding
as a hardware PFN and can return a bogus folio pointer.
Mirror queue_folios_pte_range(): handle non-present entries before looking
up a folio. Keep migration entries counted as failures, but skip other
non-present PMDs such as device-private entries.
Potential trigger: an HMM-based GPU driver migrates an anonymous THP folio
to device memory via migrate_vma_pages(), leaving a device-private PMD.
Userspace then calls mbind(), migrate_pages() or set_mempolicy_home_node()
on that range. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/migrate_device: clear stale mapping after freeing swapcache
__migrate_device_pages() reads the folio mapping before calling
folio_free_swap(). When folio_free_swap() succeeds, the folio is removed
from the swap cache, but the saved mapping still points to swap_space.
Passing the stale mapping to folio_migrate_mapping() makes it use the
mapped-folio path for a folio that is no longer in swapcache. It can then
operate on swap_space.i_pages with invalid reference accounting,
eventually triggering a folio reference count BUG.
After a successful split, nr still contains the number of pages in the
original large folio, although each resulting page is now a separate
order-0 folio. Reset nr to 1 so each split folio is processed separately,
including its own swapcache removal and mapping lookup.
Refresh the saved mapping after folio_free_swap() so the current folio
state is used during migration. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
Writing to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),
which frees every sub-buffer of the ring buffer, including the reader
page, and replaces them with newly allocated ones.
Readers of trace_pipe hold pointers into those pages. ring_buffer_peek()
looks up an event under cpu_buffer->reader_lock but returns the event
pointer after dropping the lock, and peek_next_entry() then calls
ring_buffer_event_length() and ring_buffer_event_data() on it. If the
sub-buffer order is changed in that window, the reader dereferences
freed memory:
BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430
Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002
Freed by:
free_buffer_page kernel/trace/ring_buffer.c:398 [inline]
ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444
buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221
Take trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.
This is the lock trace_pipe readers already hold across their entire
peek-and-print loop, so the swap can no longer race with a reader that
is dereferencing a peeked event. |