| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: st: Fix use-after-free race between st_remove() and st_open()
st_remove() drops the probe reference on the scsi_tape with kref_put()
and only afterwards removes its index from st_index_idr. If that was the
last reference, scsi_tape_release() frees the structure while it is
still published in the idr.
scsi_tape_get(), called from st_open(), looks up the tape in
st_index_idr and takes a reference under st_ref_mutex and
st_index_lock. remove_cdevs() does not wait for opens that are already
past chrdev_open(), so an open that is blocked on st_ref_mutex while
st_remove() holds it can take the mutex as soon as st_remove() drops it,
find the freed tpnt in the idr and call kref_get() on it:
BUG: KASAN: slab-use-after-free in st_open
Write of size 4 ...
st_open (drivers/scsi/st.c:254 drivers/scsi/st.c:1291)
chrdev_open
...
Freed by task ...:
kfree
st_remove (drivers/scsi/st.c:4512)
Remove the index from the idr before dropping the reference, all under
st_ref_mutex. A concurrent scsi_tape_get() now either runs first and
holds a valid reference that keeps the tape alive, or runs afterwards
and finds nothing, so st_open() fails with -ENXIO.
This restores the ordering st_remove() had before the conversion to
st_index_idr, where the tape was unpublished from scsi_tapes[] before
the final kref_put(). |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: xen/scsifront: Check for a NULL shadow entry on a backend response
scsifront_do_response() validates the rqid in a backend response against
VSCSIIF_MAX_REQS before using it to index info->shadow[], but then
dereferences the entry to test ->inflight without checking that the slot
is populated. Shadow slots are NULL before a command is submitted (the
host private area is zeroed at allocation) and are reset to NULL in
_scsifront_put_rqid() once a request completes, so an in-range rqid that
does not correspond to an outstanding request makes the frontend
dereference a NULL pointer.
A malicious or buggy backend can thus crash the guest by returning a
response whose rqid is in range but not in flight -- for example a
spurious response before any command has been issued, or a duplicate of
one already completed. The ring has only VSCSIIF_MAX_REQS (16) slots,
so before the first command every in-range rqid selects a NULL slot.
Reject a response whose shadow slot is not populated. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libiscsi: Reject a negative task index from parse_pdu_itt
A transport that implements parse_pdu_itt hands libiscsi an index taken
from the PDU, and both lookups bound it from above only:
if (i >= session->cmds_max)
i and cmds_max are both int, so a negative index passes and
session->cmds[i] is read from before the array.
be2iscsi produces one. beiscsi_parse_pdu() assigns the raw tag,
*index = (int)itt;
and beiscsi_complete_pdu() forwards an unsolicited NOP-In from the
hardware async ring without replacing its ITT, so the value is the
target's. It also reports the session's own age rather than the one in
the tag, which leaves the age comparison in iscsi_verify_itt() with
nothing to reject.
Bound the index from below in both lookups. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libiscsi: Validate the ITT reflected in a Reject PDU
A Reject PDU carries a copy of the header it rejects, and
iscsi_handle_reject() takes the ITT out of that copy to find the task to
clean up:
memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
...
task = iscsi_itt_to_task(conn, rejected_pdu.itt);
That value is whatever the target put there. iscsi_itt_to_task() bounds
the index against cmds_max and checks nothing else, so any task in the
pool can be named, and iscsi_nop_out_rsp() then completes it.
An index that has never been used gives a NULL task->conn: the pool is
zeroed at session setup and conn is assigned only when a task is
allocated. If the task was used and returned, iscsi_complete_task() hits
its WARN_ON_ONCE(task->state == ISCSI_TASK_FREE) and the refcount
underflows. An in-flight SCSI command is completed as successful - a 1
MiB read returned 1048576 with none of its buffer written and no
warning.
Validate the reflected ITT the way iscsi_itt_to_ctask() validates a
command ITT, and require the task to be in flight and not a SCSI
command.
[ 6.248477] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI
[ 6.249357] KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
[ 6.249951] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 7.2.0-rc5-ISCSI1-gf5098b6bae76 #1 PREEMPT(lazy)
[ 6.250718] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 6.251616] RIP: 0010:iscsi_nop_out_rsp.constprop.0+0x46/0x160
[ 6.252043] Code: c1 ea 03 48 83 ec 08 80 3c 02 00 0f 85 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 58 48 8d 7d 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c0 00 00 00 48 8b 45 60 48 39 c3 74 50 48 b8 00
[ 6.252813] RSP: 0018:ffff88806c907b80 EFLAGS: 00010206
[ 6.253042] RAX: dffffc0000000000 RBX: ffff88800607e000 RCX: ffffffff8d571a25
[ 6.253345] RDX: 000000000000000c RSI: ffff88806c907c38 RDI: 0000000000000060
[ 6.253642] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff235a504
[ 6.253947] R10: 0000000000000003 R11: 7463656e6e6f6320 R12: 0000000000000000
[ 6.254251] R13: 0000000000000000 R14: ffff88806c907c38 R15: 0000000000000000
[ 6.254549] FS: 0000000000000000(0000) GS:ffff8880d95bc000(0000) knlGS:0000000000000000
[ 6.254887] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6.255140] CR2: 00007fc393e8ffc0 CR3: 0000000005252006 CR4: 0000000000770ef0
[ 6.255439] PKRU: 55555554
[ 6.255564] Call Trace:
[ 6.255674] <IRQ>
[ 6.255768] __iscsi_complete_pdu+0x18bf/0x22a0
[ 6.256733] iscsi_complete_pdu+0x54/0xa0
[ 6.256905] iscsi_tcp_data_recv_done+0xf4/0x250
[ 6.257103] iscsi_tcp_recv_skb+0x31e/0xec0
[ 6.257680] iscsi_sw_tcp_recv+0x12f/0x390
[ 6.258061] __tcp_read_sock+0x1ab/0x810
[ 6.258853] iscsi_sw_tcp_data_ready+0x18b/0x510
[ 6.259808] tcp_data_queue+0x1f13/0x4cd0
[ 6.260567] tcp_rcv_established+0x8a5/0x3a00
[ 6.261931] tcp_v4_do_rcv+0x449/0x960
[ 6.262269] tcp_v4_rcv+0x2245/0x3bc0 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libiscsi: Validate the task named by a management response
__iscsi_complete_pdu() fetches the task for five response types from one
place and checks only that the index resolved:
case ISCSI_OP_LOGOUT_RSP:
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_SCSI_TMFUNC_RSP:
case ISCSI_OP_NOOP_IN:
task = iscsi_itt_to_task(conn, hdr->itt);
if (!task)
return ISCSI_ERR_BAD_ITT;
iscsi_itt_to_task() bounds the index against cmds_max and looks at
nothing else, so a target can name any slot in the pool, including one
that has never been used. task->conn is then NULL, and both
iscsi_nop_out_rsp() and iscsi_complete_task() dereference it. One
unsolicited NOP-In is enough; a Text Response carrying the same ITT
crashes in iscsi_complete_task() instead.
Require the task to be in flight and not a SCSI command, the way
iscsi_itt_to_ctask() does for the command opcodes.
[ 6.298634] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI
[ 6.298642] KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
[ 6.298652] CPU: 1 UID: 0 PID: 111 Comm: iscsistart Not tainted 7.2.0-rc5-ISCSI1-gf5098b6bae76 #1 PREEMPT(lazy)
[ 6.298654] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 6.298656] RIP: 0010:iscsi_nop_out_rsp.constprop.0+0x46/0x160
[ 6.298691] Code: c1 ea 03 48 83 ec 08 80 3c 02 00 0f 85 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 58 48 8d 7d 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c0 00 00 00 48 8b 45 60 48 39 c3 74 50 48 b8 00
[ 6.298698] RSP: 0018:ffff88806c907be8 EFLAGS: 00010206
[ 6.298701] RAX: dffffc0000000000 RBX: ffff888006116800 RCX: 0000000000000020
[ 6.298702] RDX: 000000000000000c RSI: ffff88800525d578 RDI: 0000000000000060
[ 6.298703] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[ 6.298706] R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000
[ 6.298706] R13: 000000000000002e R14: ffff8880056eb440 R15: ffff888006116800
[ 6.298707] FS: 00007fc02d1c2740(0000) GS:ffff8880b29bc000(0000) knlGS:0000000000000000
[ 6.298710] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6.298711] CR2: 000055fe3b56ddf8 CR3: 00000000053b9004 CR4: 0000000000770ef0
[ 6.298712] PKRU: 55555554
[ 6.298713] Call Trace:
[ 6.298714] <IRQ>
[ 6.298714] __iscsi_complete_pdu+0x13a8/0x22a0
[ 6.298758] iscsi_complete_pdu+0x54/0xa0
[ 6.298759] iscsi_tcp_hdr_recv_done+0x870/0x2c80
[ 6.298778] iscsi_tcp_recv_skb+0x31e/0xec0
[ 6.298800] iscsi_sw_tcp_recv+0x12f/0x390
[ 6.298804] __tcp_read_sock+0x1ab/0x810
[ 6.298812] iscsi_sw_tcp_data_ready+0x18b/0x510
[ 6.298814] tcp_rcv_established+0x1f56/0x3a00
[ 6.298842] tcp_v4_do_rcv+0x449/0x960
[ 6.298847] tcp_v4_rcv+0x2245/0x3bc0 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: don't drop the runtime PM reference twice in amdgpu_gpr
amdgpu_debugfs_gpr_read() drops its runtime PM reference right after
reading the wave registers. When copying them to userspace fails, it
jumps to the err label, which drops the reference a second time. A read
into a bad buffer on Navi31 either steals a reference somebody else
holds (power/runtime_usage goes from 1 to 0) or underflows the count:
amdgpu 0000:03:00.0: Runtime PM usage count underflow!
The registers are already in the kernel buffer at that point, so finish
the hardware access first and copy the buffer with a single
copy_to_user() instead of the put_user() loop with its own error path.
(cherry picked from commit 31035bbd74f7c3e10c163db875b8e67f8b50ee6a) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/exec: don't immediately add prelocked obj to array of locked objs
When a contention is detected the drm_exec object grabs a reference to
the contended object, unlocks all other objects and pre-locks the
contended one before anything else.
The problem is that it is possible that this pre-locked object was about
to be destroyed and drm_exec is now holding the last reference to it.
So we never actually see this pre-locked object again to be explicitly
locked and so also never reserve a slot for a dma_fence object on it.
Should the driver now use drm_exec_for_each_locked_object() to add a new
fence to all locked objects we eventually see a warning or even a
BUG_ON() to prevent random memory corruption.
Fix this by keeping the prelocked object out of the array of locked objs
until it was explicitly mentioned by the driver again.
If the prelocked object is never mentioned again by the driver
just unlock and drop the reference at the end of the locking loop. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Keep the predicate limit separate from program capacity
predicate_parse() adds two to nr_preds to reserve the terminal TRUE
and FALSE entries. It also uses that increased value as the limit for
parsed predicates. If the initial count is smaller than the number
actually parsed, the program can fill the allocation and subsequent
accesses can go past its end.
Keep nr_preds as the predicate limit and use a separate value for the
allocation size. This leaves space for both terminal entries and a
zeroed entry when parsing stops at the limit. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Check operator stack capacity before pushing
predicate_parse() uses the first operator stack entry before processing
any opening parentheses. A push then increments top before writing.
The existing check still permits that write when top already points to
the last allocated entry, which can access beyond the operator stack.
Reject the push when top reaches the last allocated entry. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix hist trigger timestamps for buffered events
Syzkaller triggered a WARN_ON_ONCE(!nest) warning:
WARNING: kernel/trace/ring_buffer.c:821 at ring_buffer_event_time_stamp
Call trace:
ring_buffer_event_time_stamp
hist_field_timestamp
hist_fn_call
event_hist_trigger
event_triggers_call
__event_trigger_test_discard
trace_event_buffer_commit
do_trace_event_raw_event_sched_switch
trace_event_raw_event_sched_switch
The warning is probabilistically reproducible and is related to syzkaller
executing the following commands:
echo 'prev_pid == 999999' > events/sched/sched_switch/filter
echo 'hist:keys=common_timestamp' > events/sched/sched_switch/trigger
The specific triggering process is as follows:
CPU 0 CPU 1
(context switching) (echo 'hist:keys=common_timestamp' > \
events/sched/sched_switch/trigger)
do_trace_event_raw_event_##call
trace_event_buffer_lock_reserve
if (!tr->no_filter_buffering_ref &&
trace_file->flags & EVENT_FILE_FL_FILTERED)
return entry; // return directly
event_hist_trigger_parse
hist_register_trigger
tracing_set_filter_buffering(file->tr, true);
tr->no_filter_buffering_ref++;
__trace_buffer_lock_reserve
rb_start_commit
local_inc(&cpu_buffer->committing); // skipped and not executed
trace_event_buffer_commit
__event_trigger_test_discard
event_triggers_call
event_hist_trigger
hist_fn_call
hist_field_timestamp
ring_buffer_event_time_stamp
nest = local_read(&cpu_buffer->committing);
WARN_ON_ONCE(!nest) // trigger warning
The root cause is that when an event file has a filter attached and the
hist trigger has not yet been attached, trace_event_buffer_lock_reserve()
writes the event into the per-CPU trace_buffered_event temp buffer instead
of reserving it in the ring buffer, so cpu_buffer->committing is not
incremented. When the event is later processed at commit time by a hist
trigger, hist_field_timestamp() -> ring_buffer_event_time_stamp() sees a
zero committing count, triggering WARN_ON_ONCE(!nest).
tracing_event_time_stamp() was added by commit d8279bfc5e959 ("tracing:
Add tracing_event_time_stamp() API") for exactly this case: if the event
is the per-CPU trace_buffered_event, it returns the current ring buffer
timestamp. But it never gained a caller. Use it in hist_field_timestamp(),
so that a hist trigger that races onto a buffered event records the
current time, which is only marginally later than when the event was
recorded, instead of warning and recording a bogus timestamp. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: fix use-after-free in do_tcp_getsockopt(TCP_CONGESTION)
do_tcp_getsockopt() reads icsk->icsk_ca_ops->name without holding
rcu_read_lock(). Since commit 0baf26b0fcd7 ("bpf: tcp: Support
tcp_congestion_ops in bpf"), icsk_ca_ops can point to dynamically
allocated BPF struct_ops memory that may be freed concurrently via
setsockopt(TCP_CONGESTION), leading to a use-after-free.
BUG: KASAN: slab-use-after-free in _copy_to_user+0x37/0x60
Read of size 16 at addr ffff888013505260 by task exploit/149
_copy_to_user+0x37/0x60
do_tcp_getsockopt+0x158a/0x2460 (net/ipv4/tcp.c:4585)
tcp_getsockopt+0x91/0xf0
__sys_getsockopt+0xf7/0x170
Fix this by holding rcu_read_lock() around the ca_ops->name access,
using READ_ONCE() to load icsk_ca_ops, and copying the name to a
stack buffer before releasing the lock. Also annotate the relevant
icsk_ca_ops stores with WRITE_ONCE() to fix the accompanying KCSAN
data-race issue. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)
do_tcp_getsockopt() reads icsk->icsk_ca_ops and dereferences the
get_info function pointer without rcu_read_lock(). With BPF struct_ops
congestion control, ca_ops can point to dynamically allocated memory
that is freed concurrently, resulting in a use-after-free when the
kernel dereferences or calls through the stale pointer.
BUG: KASAN: slab-use-after-free in do_tcp_getsockopt+0x2037/0x23e0
Read of size 8 at addr ffff888013701258 by task exploit/149
do_tcp_getsockopt+0x2037/0x23e0 (net/ipv4/tcp.c:4564)
tcp_getsockopt+0x91/0xf0
__sys_getsockopt+0xf7/0x170
Fix this by wrapping the ca_ops load and get_info call within
rcu_read_lock()/rcu_read_unlock(), and using READ_ONCE() to load
the icsk_ca_ops pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
dm-crypt: fix a tiny race condition in crypt_dec_pending
crypt_dec_pending reads io->error before calling atomic_dec_and_test.
Another context, for example crypt_endio called from an interrupt, may
set io->error and drop its reference between the read and the
decrement. crypt_dec_pending then drops the last reference and completes
the bio with the stale status - so a read that failed and was never
decrypted, or a write that failed, is reported as successful.
The read was placed before the decrement by commit b35f8caa0890 ("dm
crypt: wait for endio to complete before destruction"), because that
commit freed dm_crypt_io before calling bio_endio. This is no longer the
case, dm_crypt_io lives in the per-bio data now.
Read io->error after atomic_dec_and_test instead. atomic_dec_and_test is
fully ordered, so no additional barrier is needed. |
| In the Linux kernel, the following vulnerability has been resolved:
dm-integrity: fix infinite loop on discard with large tag size
When integrity_metadata handles a discard, it fills a buffer with
DISCARD_FILLER and writes it over the tags, max_blocks blocks at a
time. If the kmalloc fails, the buffer is the on-stack array
checksums_onstack and max_size is set to HASH_MAX_DIGESTSIZE. So if the
tag size is larger than HASH_MAX_DIGESTSIZE, max_blocks is zero, bi_size
is never decremented and the loop never terminates.
Fix this by using sizeof(checksums_onstack) as max_size. The array has
MAX_TAG_SIZE bytes since commit b93b6643e9b5 ("dm integrity: fix a
crash with unusually large tag size"), so max_blocks is at least 1. |
| In the Linux kernel, the following vulnerability has been resolved:
mac802154: fix data race and NULL deref on local->assoc_dev
local->assoc_dev is shared between the association path and the
association-response worker without common synchronization.
mac802154_perform_association() stores the coordinator pointer and waits
for a response. Its timeout and error paths clear the pointer and return
to mac802154_associate(), which may then free the coordinator object.
Meanwhile, mac802154_rx_mac_cmd_worker() may observe the associating bit
and enter mac802154_process_association_resp(), which dereferences
assoc_dev.
The worker's bit test and the handler's pointer dereference are not
atomic with respect to cleanup. Cleanup can clear assoc_dev between them,
causing a NULL dereference, or free the coordinator while the response
handler still uses the pointer.
The recorded result is exposed to the same window. assoc_status and
assoc_addr are written by the handler but read by the association path
while the associating bit is still set, so a second response for the same
request - a malicious one, for instance - can replace them between those
reads and leave the caller with an incoherent status and address pair.
The response handler only needs the coordinator extended address.
Replace assoc_dev with a cached address, removing the pointer lifetime
dependency. Protect the cached address and the associating bit with a
dedicated spinlock. A READ_ONCE()/WRITE_ONCE() pair would not guarantee
an atomic __le64 access on all 32-bit architectures.
wpan_dev->association_lock cannot be reused here: nl802154_associate()
holds it across rdev_associate(), hence for the whole of
mac802154_perform_association() including the wait for the response.
A response handler taking that lock would only get it once the
association has already given up.
Reset the completion, publish the cached address, and set the associating
bit while holding the lock. The response handler takes the lock, rechecks
the bit and the cached address, records the response, clears the bit, and
only then completes the waiter. Thus cleanup cannot pass the handler
between its state check and completion, and the cached 64-bit value
cannot tear.
The handler clears the bit before completing, not the woken waiter:
otherwise complete() is issued under the lock and a second (e.g.
malicious) response can reacquire it before the waiter and replace the
result. So a wait that returns success implies the bit is already clear,
and the success and negative-response paths return directly. The
transmit-error and timeout paths still clear it under assoc_lock, which
serializes any racing response against the cleanup while the call returns
the error it already selected. Both paths snapshot assoc_status and
assoc_addr under the same lock.
Both users run in process context, so a plain spinlock is sufficient.
The lock is not held while waiting for the completion. |
| In the Linux kernel, the following vulnerability has been resolved:
net/iucv: fix the recvmsg window update
iucv_sock_recvmsg() sends the HiperSockets-only AF_IUCV_FLAG_WIN without
testing the transport, so on a classic z/VM socket iucv_send_ctrl() sizes
the skb through a NULL iucv->hs_dev. SO_MSGLIMIT accepts 1, so msglimit / 2
is zero and one recvmsg() on its own socket is enough for an unprivileged
process to take a spurious disconnect.
It also calls iucv_send_ctrl() under spin_lock_bh(&message_q.lock), which
allocates GFP_KERNEL inside a section the code treats as atomic. Sending
outside that lock lets two recvmsg() reach afiucv_hs_send() at once, where
msg_recv is sampled for the advertised window and subtracted after
dev_queue_xmit() -- and sendmsg reaches that counter under lock_sock()
while recvmsg holds no socket lock, so both can subtract the same value,
the counter goes negative and the credit reaches the peer twice.
Test the transport, claim the credit with atomic_xchg() after the last
error exit and hand it back if the transmit fails, and send once the lock
is dropped. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: don't hold buffer locks across sync transaction commit in xfs_sync_sb_buf
xfs_sync_sb_buf() holds sb/rtsb buffer locks across a synchronous
xfs_trans_commit(), which flushes the CIL push workqueue internally.
If shutdown occurs during the CIL push, xfs_buf_item_unpin() needs to
lock these buffers to fail them, causing a deadlock:
setlabel: holds buf lock -> flush_workqueue(xfs-cil)
CIL push worker: xfs_buf_item_unpin -> xfs_buf_lock(same buf)
Remove the xfs_trans_bhold() calls so that commit releases the buffer
locks normally. After the sync commit, re-acquire the buffers via
mp->m_sb_bp / mp->m_rtsb_bp for the on-disk writeback. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: fix capability check in xfs
An user reported a bug where he managed to evade group's quota
by changing a file's gid to a different group id the same user
belonged to, even though quotas were enforced on both gids and the
file's size was big enough to exceed the quota's hardlimit.
Commit eba0549bc7d1 replaced a capable() call by a
has_capability_noaudit() to prevent unnecessary selinux audit messages.
Turns out that both calls have slightly different semantics even though
their documentation seems similar. Where in a nutshell:
capable() - Tests the task's effective credentials
has_ns_capability_noaudit() - Tests the task's real credentials
This most of the time has no practical difference but in some cases like
changing attrs (specifically group id in this case) through a NFS client
this will allow the quota code to use XFS_QMOPT_FORCE_RES, effectively
bypassing quota accounting checks.
Using instead ns_capable_noaudit() should fix this issue and prevent
selinux audit messages.
This also fix the remaining calls to has_capability_noaudit() |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/cancel: don't spin on local work the task can't run
io_uring_cancel_generic() refuses to sleep while any ring on the exiting
task's tctx has local work pending. It assumes the task is that ring's
submitter and that the next io_uring_try_cancel_requests() pass will run
the work. This does not hold for a ring that was still
IORING_SETUP_R_DISABLED when the task got its tctx node from
io_uring_create() or io_ringfd_register(). The submitter is set later by
IORING_REGISTER_ENABLE_RINGS, possibly from another task, and only the
submitter may run local work on an IORING_SETUP_DEFER_TASKRUN ring. To
the exiting task the work stays pending forever, the loop never reaches
schedule(), and the task trips the WARN_ON_ONCE() once and then spins in
do_exit().
An unprivileged user can set this up at will by creating a disabled
ring, having a child enable it and stop, posting to the ring with
IORING_OP_MSG_RING and exiting with a request in flight that only the
child can complete. The exiting thread burns a CPU until the child runs
or dies, and with panic_on_warn set the WARN panics the kernel.
Fix by skipping the sleep only when io_allowed_defer_tw_run() allows the
task to run the work. This is reasonable since work it cannot run cannot
complete any of its requests either, so nothing is lost by sleeping.
Drop the WARN_ON_ONCE() since handing a disabled ring to another thread
is a supported scenario, not a bug state. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: validate chunk length in the inqueue parser
SCTP chunks always include a four-byte generic header, but
sctp_inq_pop() currently accepts shorter declared lengths. A zero-length
chunk leaves chunk_end at the current header.
When ASCONF is covered by the association's SCTP-AUTH policy,
sctp_assoc_bh_rcv() can continue before the state machine performs its
normal chunk-length check. sctp_inq_pop() then returns the same malformed
chunk repeatedly and the receive softirq can lock up.
A remote SCTP peer can trigger this after establishing an association on
a kernel built with CONFIG_IP_SCTP and configured with
net.sctp.addip_enable=1 and net.sctp.auth_enable=1. The reproducer did
not require application credentials, a shared SCTP AUTH key, or
net.sctp.addip_noauth_enable=1.
On commit f967455fb2a5 ("seg6: reset IP6CB after IPv6 decapsulation"),
one zero-length ASCONF caused repeated
watchdog soft-lockup reports in a two-vCPU KVM guest. All 3 pre-trigger
health probes succeeded, while 36 of 37 post-trigger probes failed. With
this change, all 37 post-trigger probes succeeded and no equivalent
soft-lockup signature appeared.
Reject chunks shorter than the generic SCTP header at the shared inqueue
parser boundary. Mark the packet for discard before either caller can
continue processing it, while preserving the four-byte generic minimum.
Declared-length 1 through 4 controls and kernel-generated ASCONF traffic
remained healthy. The patched sctp_hello selftest passed for IPv4 and
IPv6.
The complete private reproducer and validation evidence are available
directly to maintainers on request. |
