| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
af_unix: Fix a data-race in unix_dgram_peer_wake_me().
unix_dgram_poll() calls unix_dgram_peer_wake_me() without `other`'s
lock held and check if its receive queue is full. Here we need to
use unix_recvq_full_lockless() instead of unix_recvq_full(), otherwise
KCSAN will report a data-race. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check if modulo is 0 before dividing.
[How & Why]
If a value of 0 is read, then this will cause a divide-by-0 panic. |
| In the Linux kernel, the following vulnerability has been resolved:
xsk: Fix race at socket teardown
Fix a race in the xsk socket teardown code that can lead to a NULL pointer
dereference splat. The current xsk unbind code in xsk_unbind_dev() starts by
setting xs->state to XSK_UNBOUND, sets xs->dev to NULL and then waits for any
NAPI processing to terminate using synchronize_net(). After that, the release
code starts to tear down the socket state and free allocated memory.
BUG: kernel NULL pointer dereference, address: 00000000000000c0
PGD 8000000932469067 P4D 8000000932469067 PUD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 25 PID: 69132 Comm: grpcpp_sync_ser Tainted: G I 5.16.0+ #2
Hardware name: Dell Inc. PowerEdge R730/0599V5, BIOS 1.2.10 03/09/2015
RIP: 0010:__xsk_sendmsg+0x2c/0x690
[...]
RSP: 0018:ffffa2348bd13d50 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000040 RCX: ffff8d5fc632d258
RDX: 0000000000400000 RSI: ffffa2348bd13e10 RDI: ffff8d5fc5489800
RBP: ffffa2348bd13db0 R08: 0000000000000000 R09: 00007ffffffff000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8d5fc5489800
R13: ffff8d5fcb0f5140 R14: ffff8d5fcb0f5140 R15: 0000000000000000
FS: 00007f991cff9400(0000) GS:ffff8d6f1f700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000c0 CR3: 0000000114888005 CR4: 00000000001706e0
Call Trace:
<TASK>
? aa_sk_perm+0x43/0x1b0
xsk_sendmsg+0xf0/0x110
sock_sendmsg+0x65/0x70
__sys_sendto+0x113/0x190
? debug_smp_processor_id+0x17/0x20
? fpregs_assert_state_consistent+0x23/0x50
? exit_to_user_mode_prepare+0xa5/0x1d0
__x64_sys_sendto+0x29/0x30
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
There are two problems with the current code. First, setting xs->dev to NULL
before waiting for all users to stop using the socket is not correct. The
entry to the data plane functions xsk_poll(), xsk_sendmsg(), and xsk_recvmsg()
are all guarded by a test that xs->state is in the state XSK_BOUND and if not,
it returns right away. But one process might have passed this test but still
have not gotten to the point in which it uses xs->dev in the code. In this
interim, a second process executing xsk_unbind_dev() might have set xs->dev to
NULL which will lead to a crash for the first process. The solution here is
just to get rid of this NULL assignment since it is not used anymore. Before
commit 42fddcc7c64b ("xsk: use state member for socket synchronization"),
xs->dev was the gatekeeper to admit processes into the data plane functions,
but it was replaced with the state variable xs->state in the aforementioned
commit.
The second problem is that synchronize_net() does not wait for any process in
xsk_poll(), xsk_sendmsg(), or xsk_recvmsg() to complete, which means that the
state they rely on might be cleaned up prematurely. This can happen when the
notifier gets called (at driver unload for example) as it uses xsk_unbind_dev().
Solve this by extending the RCU critical region from just the ndo_xsk_wakeup
to the whole functions mentioned above, so that both the test of xs->state ==
XSK_BOUND and the last use of any member of xs is covered by the RCU critical
section. This will guarantee that when synchronize_net() completes, there will
be no processes left executing xsk_poll(), xsk_sendmsg(), or xsk_recvmsg() and
state can be cleaned up safely. Note that we need to drop the RCU lock for the
skb xmit path as it uses functions that might sleep. Due to this, we have to
retest the xs->state after we grab the mutex that protects the skb xmit code
from, among a number of things, an xsk_unbind_dev() being executed from the
notifier at the same time. |
| In the Linux kernel, the following vulnerability has been resolved:
ibmvnic: fix race between xmit and reset
There is a race between reset and the transmit paths that can lead to
ibmvnic_xmit() accessing an scrq after it has been freed in the reset
path. It can result in a crash like:
Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
BUG: Kernel NULL pointer dereference on read at 0x00000000
Faulting instruction address: 0xc0080000016189f8
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c0080000016189f8] ibmvnic_xmit+0x60/0xb60 [ibmvnic]
LR [c000000000c0046c] dev_hard_start_xmit+0x11c/0x280
Call Trace:
[c008000001618f08] ibmvnic_xmit+0x570/0xb60 [ibmvnic] (unreliable)
[c000000000c0046c] dev_hard_start_xmit+0x11c/0x280
[c000000000c9cfcc] sch_direct_xmit+0xec/0x330
[c000000000bfe640] __dev_xmit_skb+0x3a0/0x9d0
[c000000000c00ad4] __dev_queue_xmit+0x394/0x730
[c008000002db813c] __bond_start_xmit+0x254/0x450 [bonding]
[c008000002db8378] bond_start_xmit+0x40/0xc0 [bonding]
[c000000000c0046c] dev_hard_start_xmit+0x11c/0x280
[c000000000c00ca4] __dev_queue_xmit+0x564/0x730
[c000000000cf97e0] neigh_hh_output+0xd0/0x180
[c000000000cfa69c] ip_finish_output2+0x31c/0x5c0
[c000000000cfd244] __ip_queue_xmit+0x194/0x4f0
[c000000000d2a3c4] __tcp_transmit_skb+0x434/0x9b0
[c000000000d2d1e0] __tcp_retransmit_skb+0x1d0/0x6a0
[c000000000d2d984] tcp_retransmit_skb+0x34/0x130
[c000000000d310e8] tcp_retransmit_timer+0x388/0x6d0
[c000000000d315ec] tcp_write_timer_handler+0x1bc/0x330
[c000000000d317bc] tcp_write_timer+0x5c/0x200
[c000000000243270] call_timer_fn+0x50/0x1c0
[c000000000243704] __run_timers.part.0+0x324/0x460
[c000000000243894] run_timer_softirq+0x54/0xa0
[c000000000ea713c] __do_softirq+0x15c/0x3e0
[c000000000166258] __irq_exit_rcu+0x158/0x190
[c000000000166420] irq_exit+0x20/0x40
[c00000000002853c] timer_interrupt+0x14c/0x2b0
[c000000000009a00] decrementer_common_virt+0x210/0x220
--- interrupt: 900 at plpar_hcall_norets_notrace+0x18/0x2c
The immediate cause of the crash is the access of tx_scrq in the following
snippet during a reset, where the tx_scrq can be either NULL or an address
that will soon be invalid:
ibmvnic_xmit()
{
...
tx_scrq = adapter->tx_scrq[queue_num];
txq = netdev_get_tx_queue(netdev, queue_num);
ind_bufp = &tx_scrq->ind_buf;
if (test_bit(0, &adapter->resetting)) {
...
}
But beyond that, the call to ibmvnic_xmit() itself is not safe during a
reset and the reset path attempts to avoid this by stopping the queue in
ibmvnic_cleanup(). However just after the queue was stopped, an in-flight
ibmvnic_complete_tx() could have restarted the queue even as the reset is
progressing.
Since the queue was restarted we could get a call to ibmvnic_xmit() which
can then access the bad tx_scrq (or other fields).
We cannot however simply have ibmvnic_complete_tx() check the ->resetting
bit and skip starting the queue. This can race at the "back-end" of a good
reset which just restarted the queue but has not cleared the ->resetting
bit yet. If we skip restarting the queue due to ->resetting being true,
the queue would remain stopped indefinitely potentially leading to transmit
timeouts.
IOW ->resetting is too broad for this purpose. Instead use a new flag
that indicates whether or not the queues are active. Only the open/
reset paths control when the queues are active. ibmvnic_complete_tx()
and others wake up the queue only if the queue is marked active.
So we will have:
A. reset/open thread in ibmvnic_cleanup() and __ibmvnic_open()
->resetting = true
->tx_queues_active = false
disable tx queues
...
->tx_queues_active = true
start tx queues
B. Tx interrupt in ibmvnic_complete_tx():
if (->tx_queues_active)
netif_wake_subqueue();
To ensure that ->tx_queues_active and state of the queues are consistent,
we need a lock which:
- must also be taken in the interrupt path (ibmvnic_complete_tx())
- shared across the multiple
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: qcom: uefisecapp: fix efivars registration race
Since the conversion to using the TZ allocator, the efivars service is
registered before the memory pool has been allocated, something which
can lead to a NULL-pointer dereference in case of a racing EFI variable
access.
Make sure that all resources have been set up before registering the
efivars. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: fix kernel BUG when userfaultfd_move encounters swapcache
userfaultfd_move() checks whether the PTE entry is present or a
swap entry.
- If the PTE entry is present, move_present_pte() handles folio
migration by setting:
src_folio->index = linear_page_index(dst_vma, dst_addr);
- If the PTE entry is a swap entry, move_swap_pte() simply copies
the PTE to the new dst_addr.
This approach is incorrect because, even if the PTE is a swap entry,
it can still reference a folio that remains in the swap cache.
This creates a race window between steps 2 and 4.
1. add_to_swap: The folio is added to the swapcache.
2. try_to_unmap: PTEs are converted to swap entries.
3. pageout: The folio is written back.
4. Swapcache is cleared.
If userfaultfd_move() occurs in the window between steps 2 and 4,
after the swap PTE has been moved to the destination, accessing the
destination triggers do_swap_page(), which may locate the folio in
the swapcache. However, since the folio's index has not been updated
to match the destination VMA, do_swap_page() will detect a mismatch.
This can result in two critical issues depending on the system
configuration.
If KSM is disabled, both small and large folios can trigger a BUG
during the add_rmap operation due to:
page_pgoff(folio, page) != linear_page_index(vma, address)
[ 13.336953] page: refcount:6 mapcount:1 mapping:00000000f43db19c index:0xffffaf150 pfn:0x4667c
[ 13.337520] head: order:2 mapcount:1 entire_mapcount:0 nr_pages_mapped:1 pincount:0
[ 13.337716] memcg:ffff00000405f000
[ 13.337849] anon flags: 0x3fffc0000020459(locked|uptodate|dirty|owner_priv_1|head|swapbacked|node=0|zone=0|lastcpupid=0xffff)
[ 13.338630] raw: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361
[ 13.338831] raw: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000
[ 13.339031] head: 03fffc0000020459 ffff80008507b538 ffff80008507b538 ffff000006260361
[ 13.339204] head: 0000000ffffaf150 0000000000004000 0000000600000000 ffff00000405f000
[ 13.339375] head: 03fffc0000000202 fffffdffc0199f01 ffffffff00000000 0000000000000001
[ 13.339546] head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
[ 13.339736] page dumped because: VM_BUG_ON_PAGE(page_pgoff(folio, page) != linear_page_index(vma, address))
[ 13.340190] ------------[ cut here ]------------
[ 13.340316] kernel BUG at mm/rmap.c:1380!
[ 13.340683] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[ 13.340969] Modules linked in:
[ 13.341257] CPU: 1 UID: 0 PID: 107 Comm: a.out Not tainted 6.14.0-rc3-gcf42737e247a-dirty #299
[ 13.341470] Hardware name: linux,dummy-virt (DT)
[ 13.341671] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 13.341815] pc : __page_check_anon_rmap+0xa0/0xb0
[ 13.341920] lr : __page_check_anon_rmap+0xa0/0xb0
[ 13.342018] sp : ffff80008752bb20
[ 13.342093] x29: ffff80008752bb20 x28: fffffdffc0199f00 x27: 0000000000000001
[ 13.342404] x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000001
[ 13.342575] x23: 0000ffffaf0d0000 x22: 0000ffffaf0d0000 x21: fffffdffc0199f00
[ 13.342731] x20: fffffdffc0199f00 x19: ffff000006210700 x18: 00000000ffffffff
[ 13.342881] x17: 6c203d2120296567 x16: 6170202c6f696c6f x15: 662866666f67705f
[ 13.343033] x14: 6567617028454741 x13: 2929737365726464 x12: ffff800083728ab0
[ 13.343183] x11: ffff800082996bf8 x10: 0000000000000fd7 x9 : ffff80008011bc40
[ 13.343351] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000829eebf8
[ 13.343498] x5 : c0000000fffff000 x4 : 0000000000000000 x3 : 0000000000000000
[ 13.343645] x2 : 0000000000000000 x1 : ffff0000062db980 x0 : 000000000000005f
[ 13.343876] Call trace:
[ 13.344045] __page_check_anon_rmap+0xa0/0xb0 (P)
[ 13.344234] folio_add_anon_rmap_ptes+0x22c/0x320
[ 13.344333] do_swap_page+0x1060/0x1400
[ 13.344417] __handl
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
l2tp: close all race conditions in l2tp_tunnel_register()
The code in l2tp_tunnel_register() is racy in several ways:
1. It modifies the tunnel socket _after_ publishing it.
2. It calls setup_udp_tunnel_sock() on an existing socket without
locking.
3. It changes sock lock class on fly, which triggers many syzbot
reports.
This patch amends all of them by moving socket initialization code
before publishing and under sock lock. As suggested by Jakub, the
l2tp lockdep class is not necessary as we can just switch to
bh_lock_sock_nested(). |
| In the Linux kernel, the following vulnerability has been resolved:
exfat: fix random stack corruption after get_block
When get_block is called with a buffer_head allocated on the stack, such
as do_mpage_readpage, stack corruption due to buffer_head UAF may occur in
the following race condition situation.
<CPU 0> <CPU 1>
mpage_read_folio
<<bh on stack>>
do_mpage_readpage
exfat_get_block
bh_read
__bh_read
get_bh(bh)
submit_bh
wait_on_buffer
...
end_buffer_read_sync
__end_buffer_read_notouch
unlock_buffer
<<keep going>>
...
...
...
...
<<bh is not valid out of mpage_read_folio>>
.
.
another_function
<<variable A on stack>>
put_bh(bh)
atomic_dec(bh->b_count)
* stack corruption here *
This patch returns -EAGAIN if a folio does not have buffers when bh_read
needs to be called. By doing this, the caller can fallback to functions
like block_read_full_folio(), create a buffer_head in the folio, and then
call get_block again.
Let's do not call bh_read() with on-stack buffer_head. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: release flow rule object from commit path
No need to postpone this to the commit release path, since no packets
are walking over this object, this is accessed from control plane only.
This helped uncovered UAF triggered by races with the netlink notifier. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: netlink notifier might race to release objects
commit release path is invoked via call_rcu and it runs lockless to
release the objects after rcu grace period. The netlink notifier handler
might win race to remove objects that the transaction context is still
referencing from the commit release path.
Call rcu_barrier() to ensure pending rcu callbacks run to completion
if the list of transactions to be destroyed is not empty. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan
make_uffd_wp_pte() was previously doing:
pte = ptep_get(ptep);
ptep_modify_prot_start(ptep);
pte = pte_mkuffd_wp(pte);
ptep_modify_prot_commit(ptep, pte);
But if another thread accessed or dirtied the pte between the first 2
calls, this could lead to loss of that information. Since
ptep_modify_prot_start() gets and clears atomically, the following is the
correct pattern and prevents any possible race. Any access after the
first call would see an invalid pte and cause a fault:
pte = ptep_modify_prot_start(ptep);
pte = pte_mkuffd_wp(pte);
ptep_modify_prot_commit(ptep, pte); |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Disable idle reallow as part of command/gpint execution
[Why]
Workaroud for a race condition where DMCUB is in the process of
committing to IPS1 during the handshake causing us to miss the
transition into IPS2 and touch the INBOX1 RPTR causing a HW hang.
[How]
Disable the reallow to ensure that we have enough of a gap between entry
and exit and we're not seeing back-to-back wake_and_executes. |
| CISA Thorium accepts a stream split size of zero then divides by this value. A remote, authenticated attacker could cause the service to crash. Fixed in commit 89101a6. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Use del_timer_sync in fw reset flow of halting poll
Substitute del_timer() with del_timer_sync() in fw reset polling
deactivation flow, in order to prevent a race condition which occurs
when del_timer() is called and timer is deactivated while another
process is handling the timer interrupt. A situation that led to
the following call trace:
RIP: 0010:run_timer_softirq+0x137/0x420
<IRQ>
recalibrate_cpu_khz+0x10/0x10
ktime_get+0x3e/0xa0
? sched_clock_cpu+0xb/0xc0
__do_softirq+0xf5/0x2ea
irq_exit_rcu+0xc1/0xf0
sysvec_apic_timer_interrupt+0x9e/0xc0
asm_sysvec_apic_timer_interrupt+0x12/0x20
</IRQ> |
| The Object Request Broker (ORB) in IBM SDK, Java Technology Edition 7.1.0.0 through 7.1.5.18 and 8.0.0.0 through 8.0.8.26 is vulnerable to remote denial of service, caused by a race condition in the management of ORB listener threads. |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/smp: do not decrement idle task preempt count in CPU offline
With PREEMPT_COUNT=y, when a CPU is offlined and then onlined again, we
get:
BUG: scheduling while atomic: swapper/1/0/0x00000000
no locks held by swapper/1/0.
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.0-rc2+ #100
Call Trace:
dump_stack_lvl+0xac/0x108
__schedule_bug+0xac/0xe0
__schedule+0xcf8/0x10d0
schedule_idle+0x3c/0x70
do_idle+0x2d8/0x4a0
cpu_startup_entry+0x38/0x40
start_secondary+0x2ec/0x3a0
start_secondary_prolog+0x10/0x14
This is because powerpc's arch_cpu_idle_dead() decrements the idle task's
preempt count, for reasons explained in commit a7c2bb8279d2 ("powerpc:
Re-enable preemption before cpu_die()"), specifically "start_secondary()
expects a preempt_count() of 0."
However, since commit 2c669ef6979c ("powerpc/preempt: Don't touch the idle
task's preempt_count during hotplug") and commit f1a0a376ca0c ("sched/core:
Initialize the idle task with preemption disabled"), that justification no
longer holds.
The idle task isn't supposed to re-enable preemption, so remove the
vestigial preempt_enable() from the CPU offline path.
Tested with pseries and powernv in qemu, and pseries on PowerVM. |
| In the Linux kernel, the following vulnerability has been resolved:
erofs: fix race in z_erofs_get_gbuf()
In z_erofs_get_gbuf(), the current task may be migrated to another
CPU between `z_erofs_gbuf_id()` and `spin_lock(&gbuf->lock)`.
Therefore, z_erofs_put_gbuf() will trigger the following issue
which was found by stress test:
<2>[772156.434168] kernel BUG at fs/erofs/zutil.c:58!
..
<4>[772156.435007]
<4>[772156.439237] CPU: 0 PID: 3078 Comm: stress Kdump: loaded Tainted: G E 6.10.0-rc7+ #2
<4>[772156.439239] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 1.0.0 01/01/2017
<4>[772156.439241] pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
<4>[772156.439243] pc : z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.439252] lr : z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
..
<6>[772156.445958] stress (3127): drop_caches: 1
<4>[772156.446120] Call trace:
<4>[772156.446121] z_erofs_put_gbuf+0x64/0x70 [erofs]
<4>[772156.446761] z_erofs_lz4_decompress+0x600/0x6a0 [erofs]
<4>[772156.446897] z_erofs_decompress_queue+0x740/0xa10 [erofs]
<4>[772156.447036] z_erofs_runqueue+0x428/0x8c0 [erofs]
<4>[772156.447160] z_erofs_readahead+0x224/0x390 [erofs]
.. |
| Wasmtime is an open source runtime for WebAssembly. Under certain concurrent event orderings, a `wasmtime::Engine`'s internal type registry was susceptible to double-unregistration bugs due to a race condition, leading to panics and potentially type registry corruption. That registry corruption could, following an additional and particular sequence of concurrent events, lead to violations of WebAssembly's control-flow integrity (CFI) and type safety. Users that do not use `wasmtime::Engine` across multiple threads are not affected. Users that only create new modules across threads over time are additionally not affected. Reproducing this bug requires creating and dropping multiple type instances (such as `wasmtime::FuncType` or `wasmtime::ArrayType`) concurrently on multiple threads, where all types are associated with the same `wasmtime::Engine`. **Wasm guests cannot trigger this bug.** See the "References" section below for a list of Wasmtime types-related APIs that are affected. Wasmtime maintains an internal registry of types within a `wasmtime::Engine` and an engine is shareable across threads. Types can be created and referenced through creation of a `wasmtime::Module`, creation of `wasmtime::FuncType`, or a number of other APIs where the host creates a function (see "References" below). Each of these cases interacts with an engine to deduplicate type information and manage type indices that are used to implement type checks in WebAssembly's `call_indirect` function, for example. This bug is a race condition in this management where the internal type registry could be corrupted to trigger an assert or contain invalid state. Wasmtime's internal representation of a type has individual types (e.g. one-per-host-function) maintain a registration count of how many time it's been used. Types additionally have state within an engine behind a read-write lock such as lookup/deduplication information. The race here is a time-of-check versus time-of-use (TOCTOU) bug where one thread atomically decrements a type entry's registration count, observes zero registrations, and then acquires a lock in order to unregister that entry. However, between when this first thread observed the zero-registration count and when it acquires that lock, another thread could perform the following sequence of events: re-register another copy of the type, which deduplicates to that same entry, resurrecting it and incrementing its registration count; then drop the type and decrement its registration count; observe that the registration count is now zero; acquire the type registry lock; and finally unregister the type. Now, when the original thread finally acquires the lock and unregisters the entry, it is the second time this entry has been unregistered. This bug was originally introduced in Wasmtime 19's development of the WebAssembly GC proposal. This bug affects users who are not using the GC proposal, however, and affects Wasmtime in its default configuration even when the GC proposal is disabled. Wasmtime users using 19.0.0 and after are all affected by this issue. We have released the following Wasmtime versions, all of which have a fix for this bug: * 21.0.2 * 22.0.1 * 23.0.3 * 24.0.1 * 25.0.2. If your application creates and drops Wasmtime types on multiple threads concurrently, there are no known workarounds. Users are encouraged to upgrade to a patched release. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/cpum_sf: Fix and protect memory allocation of SDBs with mutex
Reservation of the PMU hardware is done at first event creation
and is protected by a pair of mutex_lock() and mutex_unlock().
After reservation of the PMU hardware the memory
required for the PMUs the event is to be installed on is
allocated by allocate_buffers() and alloc_sampling_buffer().
This done outside of the mutex protection.
Without mutex protection two or more concurrent invocations of
perf_event_init() may run in parallel.
This can lead to allocation of Sample Data Blocks (SDBs)
multiple times for the same PMU.
Prevent this and protect memory allocation of SDBs by
mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
gve: guard XDP xmit NDO on existence of xdp queues
In GVE, dedicated XDP queues only exist when an XDP program is installed
and the interface is up. As such, the NDO XDP XMIT callback should
return early if either of these conditions are false.
In the case of no loaded XDP program, priv->num_xdp_queues=0 which can
cause a divide-by-zero error, and in the case of interface down,
num_xdp_queues remains untouched to persist XDP queue count for the next
interface up, but the TX pointer itself would be NULL.
The XDP xmit callback also needs to synchronize with a device
transitioning from open to close. This synchronization will happen via
the GVE_PRIV_FLAGS_NAPI_ENABLED bit along with a synchronize_net() call,
which waits for any RCU critical sections at call-time to complete. |
