| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec
nvmet_tcp_build_pdu_iovec() could walk past cmd->req.sg when a PDU
length or offset exceeds sg_cnt and then use bogus sg->length/offset
values, leading to _copy_to_iter() GPF/KASAN. Guard sg_idx, remaining
entries, and sg->length/offset before building the bvec. |
| 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:
net: octeon_ep_vf: fix free_irq dev_id mismatch in IRQ rollback
octep_vf_request_irqs() requests MSI-X queue IRQs with dev_id set to
ioq_vector. If request_irq() fails part-way, the rollback loop calls
free_irq() with dev_id set to 'oct', which does not match the original
dev_id and may leave the irqaction registered.
This can keep IRQ handlers alive while ioq_vector is later freed during
unwind/teardown, leading to a use-after-free or crash when an interrupt
fires.
Fix the error path to free IRQs with the same ioq_vector dev_id used
during request_irq(). |
| In the Linux kernel, the following vulnerability has been resolved:
dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()
syzbot was able to crash the kernel in rt6_uncached_list_flush_dev()
in an interesting way [1]
Crash happens in list_del_init()/INIT_LIST_HEAD() while writing
list->prev, while the prior write on list->next went well.
static inline void INIT_LIST_HEAD(struct list_head *list)
{
WRITE_ONCE(list->next, list); // This went well
WRITE_ONCE(list->prev, list); // Crash, @list has been freed.
}
Issue here is that rt6_uncached_list_del() did not attempt to lock
ul->lock, as list_empty(&rt->dst.rt_uncached) returned
true because the WRITE_ONCE(list->next, list) happened on the other CPU.
We might use list_del_init_careful() and list_empty_careful(),
or make sure rt6_uncached_list_del() always grabs the spinlock
whenever rt->dst.rt_uncached_list has been set.
A similar fix is neeed for IPv4.
[1]
BUG: KASAN: slab-use-after-free in INIT_LIST_HEAD include/linux/list.h:46 [inline]
BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:296 [inline]
BUG: KASAN: slab-use-after-free in rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]
BUG: KASAN: slab-use-after-free in rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020
Write of size 8 at addr ffff8880294cfa78 by task kworker/u8:14/3450
CPU: 0 UID: 0 PID: 3450 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: netns cleanup_net
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
INIT_LIST_HEAD include/linux/list.h:46 [inline]
list_del_init include/linux/list.h:296 [inline]
rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]
rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020
addrconf_ifdown+0x143/0x18a0 net/ipv6/addrconf.c:3853
addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
call_netdevice_notifiers net/core/dev.c:2282 [inline]
netif_close_many+0x29c/0x410 net/core/dev.c:1785
unregister_netdevice_many_notify+0xb50/0x2330 net/core/dev.c:12353
ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248
cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Allocated by task 803:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270
dst_alloc+0x105/0x170 net/core/dst.c:89
ip6_dst_alloc net/ipv6/route.c:342 [inline]
icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333
mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844
mld_send_cr net/ipv6/mcast.c:2154 [inline]
mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entr
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: SOF: ipc4-topology: Correct the allocation size for bytes controls
The size of the data behind of scontrol->ipc_control_data for bytes
controls is:
[1] sizeof(struct sof_ipc4_control_data) + // kernel only struct
[2] sizeof(struct sof_abi_hdr)) + payload
The max_size specifies the size of [2] and it is coming from topology.
Change the function to take this into account and allocate adequate amount
of memory behind scontrol->ipc_control_data.
With the change we will allocate [1] amount more memory to be able to hold
the full size of data. |
| In the Linux kernel, the following vulnerability has been resolved:
rpmsg: core: fix race in driver_override_show() and use core helper
The driver_override_show function reads the driver_override string
without holding the device_lock. However, the store function modifies
and frees the string while holding the device_lock. This creates a race
condition where the string can be freed by the store function while
being read by the show function, leading to a use-after-free.
To fix this, replace the rpmsg_string_attr macro with explicit show and
store functions. The new driver_override_store uses the standard
driver_set_override helper. Since the introduction of
driver_set_override, the comments in include/linux/rpmsg.h have stated
that this helper must be used to set or clear driver_override, but the
implementation was not updated until now.
Because driver_set_override modifies and frees the string while holding
the device_lock, the new driver_override_show now correctly holds the
device_lock during the read operation to prevent the race.
Additionally, since rpmsg_string_attr has only ever been used for
driver_override, removing the macro simplifies the code. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not free data reservation in fallback from inline due to -ENOSPC
If we fail to create an inline extent due to -ENOSPC, we will attempt to
go through the normal COW path, reserve an extent, create an ordered
extent, etc. However we were always freeing the reserved qgroup data,
which is wrong since we will use data. Fix this by freeing the reserved
qgroup data in __cow_file_range_inline() only if we are not doing the
fallback (ret is <= 0). |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix reservation leak in some error paths when inserting inline extent
If we fail to allocate a path or join a transaction, we return from
__cow_file_range_inline() without freeing the reserved qgroup data,
resulting in a leak. Fix this by ensuring we call btrfs_qgroup_free_data()
in such cases. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtl8xxxu: fix slab-out-of-bounds in rtl8xxxu_sta_add
The driver does not set hw->sta_data_size, which causes mac80211 to
allocate insufficient space for driver private station data in
__sta_info_alloc(). When rtl8xxxu_sta_add() accesses members of
struct rtl8xxxu_sta_info through sta->drv_priv, this results in a
slab-out-of-bounds write.
KASAN report on RISC-V (VisionFive 2) with RTL8192EU adapter:
BUG: KASAN: slab-out-of-bounds in rtl8xxxu_sta_add+0x31c/0x346
Write of size 8 at addr ffffffd6d3e9ae88 by task kworker/u16:0/12
Set hw->sta_data_size to sizeof(struct rtl8xxxu_sta_info) during
probe, similar to how hw->vif_data_size is configured. This ensures
mac80211 allocates sufficient space for the driver's per-station
private data.
Tested on StarFive VisionFive 2 v1.2A board. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/sva: invalidate stale IOTLB entries for kernel address space
Introduce a new IOMMU interface to flush IOTLB paging cache entries for
the CPU kernel address space. This interface is invoked from the x86
architecture code that manages combined user and kernel page tables,
specifically before any kernel page table page is freed and reused.
This addresses the main issue with vfree() which is a common occurrence
and can be triggered by unprivileged users. While this resolves the
primary problem, it doesn't address some extremely rare case related to
memory unplug of memory that was present as reserved memory at boot, which
cannot be triggered by unprivileged users. The discussion can be found at
the link below.
Enable SVA on x86 architecture since the IOMMU can now receive
notification to flush the paging cache before freeing the CPU kernel page
table pages. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: always detect conflicting inodes when logging inode refs
After rename exchanging (either with the rename exchange operation or
regular renames in multiple non-atomic steps) two inodes and at least
one of them is a directory, we can end up with a log tree that contains
only of the inodes and after a power failure that can result in an attempt
to delete the other inode when it should not because it was not deleted
before the power failure. In some case that delete attempt fails when
the target inode is a directory that contains a subvolume inside it, since
the log replay code is not prepared to deal with directory entries that
point to root items (only inode items).
1) We have directories "dir1" (inode A) and "dir2" (inode B) under the
same parent directory;
2) We have a file (inode C) under directory "dir1" (inode A);
3) We have a subvolume inside directory "dir2" (inode B);
4) All these inodes were persisted in a past transaction and we are
currently at transaction N;
5) We rename the file (inode C), so at btrfs_log_new_name() we update
inode C's last_unlink_trans to N;
6) We get a rename exchange for "dir1" (inode A) and "dir2" (inode B),
so after the exchange "dir1" is inode B and "dir2" is inode A.
During the rename exchange we call btrfs_log_new_name() for inodes
A and B, but because they are directories, we don't update their
last_unlink_trans to N;
7) An fsync against the file (inode C) is done, and because its inode
has a last_unlink_trans with a value of N we log its parent directory
(inode A) (through btrfs_log_all_parents(), called from
btrfs_log_inode_parent()).
8) So we end up with inode B not logged, which now has the old name
of inode A. At copy_inode_items_to_log(), when logging inode A, we
did not check if we had any conflicting inode to log because inode
A has a generation lower than the current transaction (created in
a past transaction);
9) After a power failure, when replaying the log tree, since we find that
inode A has a new name that conflicts with the name of inode B in the
fs tree, we attempt to delete inode B... this is wrong since that
directory was never deleted before the power failure, and because there
is a subvolume inside that directory, attempting to delete it will fail
since replay_dir_deletes() and btrfs_unlink_inode() are not prepared
to deal with dir items that point to roots instead of inodes.
When that happens the mount fails and we get a stack trace like the
following:
[87.2314] BTRFS info (device dm-0): start tree-log replay
[87.2318] BTRFS critical (device dm-0): failed to delete reference to subvol, root 5 inode 256 parent 259
[87.2332] ------------[ cut here ]------------
[87.2338] BTRFS: Transaction aborted (error -2)
[87.2346] WARNING: CPU: 1 PID: 638968 at fs/btrfs/inode.c:4345 __btrfs_unlink_inode+0x416/0x440 [btrfs]
[87.2368] Modules linked in: btrfs loop dm_thin_pool (...)
[87.2470] CPU: 1 UID: 0 PID: 638968 Comm: mount Tainted: G W 6.18.0-rc7-btrfs-next-218+ #2 PREEMPT(full)
[87.2489] Tainted: [W]=WARN
[87.2494] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[87.2514] RIP: 0010:__btrfs_unlink_inode+0x416/0x440 [btrfs]
[87.2538] Code: c0 89 04 24 (...)
[87.2568] RSP: 0018:ffffc0e741f4b9b8 EFLAGS: 00010286
[87.2574] RAX: 0000000000000000 RBX: ffff9d3ec8a6cf60 RCX: 0000000000000000
[87.2582] RDX: 0000000000000002 RSI: ffffffff84ab45a1 RDI: 00000000ffffffff
[87.2591] RBP: ffff9d3ec8a6ef20 R08: 0000000000000000 R09: ffffc0e741f4b840
[87.2599] R10: ffff9d45dc1fffa8 R11: 0000000000000003 R12: ffff9d3ee26d77e0
[87.2608] R13: ffffc0e741f4ba98 R14: ffff9d4458040800 R15: ffff9d44b6b7ca10
[87.2618] FS: 00007f7b9603a840(0000) GS:ffff9d4658982000(0000) knlGS:0000000000000000
[87.
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
dm-verity: disable recursive forward error correction
There are two problems with the recursive correction:
1. It may cause denial-of-service. In fec_read_bufs, there is a loop that
has 253 iterations. For each iteration, we may call verity_hash_for_block
recursively. There is a limit of 4 nested recursions - that means that
there may be at most 253^4 (4 billion) iterations. Red Hat QE team
actually created an image that pushes dm-verity to this limit - and this
image just makes the udev-worker process get stuck in the 'D' state.
2. It doesn't work. In fec_read_bufs we store data into the variable
"fio->bufs", but fio bufs is shared between recursive invocations, if
"verity_hash_for_block" invoked correction recursively, it would
overwrite partially filled fio->bufs. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gem: Zero-initialize the eb.vma array in i915_gem_do_execbuffer
Initialize the eb.vma array with values of 0 when the eb structure is
first set up. In particular, this sets the eb->vma[i].vma pointers to
NULL, simplifying cleanup and getting rid of the bug described below.
During the execution of eb_lookup_vmas(), the eb->vma array is
successively filled up with struct eb_vma objects. This process includes
calling eb_add_vma(), which might fail; however, even in the event of
failure, eb->vma[i].vma is set for the currently processed buffer.
If eb_add_vma() fails, eb_lookup_vmas() returns with an error, which
prompts a call to eb_release_vmas() to clean up the mess. Since
eb_lookup_vmas() might fail during processing any (possibly not first)
buffer, eb_release_vmas() checks whether a buffer's vma is NULL to know
at what point did the lookup function fail.
In eb_lookup_vmas(), eb->vma[i].vma is set to NULL if either the helper
function eb_lookup_vma() or eb_validate_vma() fails. eb->vma[i+1].vma is
set to NULL in case i915_gem_object_userptr_submit_init() fails; the
current one needs to be cleaned up by eb_release_vmas() at this point,
so the next one is set. If eb_add_vma() fails, neither the current nor
the next vma is set to NULL, which is a source of a NULL deref bug
described in the issue linked in the Closes tag.
When entering eb_lookup_vmas(), the vma pointers are set to the slab
poison value, instead of NULL. This doesn't matter for the actual
lookup, since it gets overwritten anyway, however the eb_release_vmas()
function only recognizes NULL as the stopping value, hence the pointers
are being set to NULL as they go in case of intermediate failure. This
patch changes the approach to filling them all with NULL at the start
instead, rather than handling that manually during failure.
(cherry picked from commit 08889b706d4f0b8d2352b7ca29c2d8df4d0787cd) |
| In the Linux kernel, the following vulnerability has been resolved:
erspan: Initialize options_len before referencing options.
The struct ip_tunnel_info has a flexible array member named
options that is protected by a counted_by(options_len)
attribute.
The compiler will use this information to enforce runtime bounds
checking deployed by FORTIFY_SOURCE string helpers.
As laid out in the GCC documentation, the counter must be
initialized before the first reference to the flexible array
member.
After scanning through the files that use struct ip_tunnel_info
and also refer to options or options_len, it appears the normal
case is to use the ip_tunnel_info_opts_set() helper.
Said helper would initialize options_len properly before copying
data into options, however in the GRE ERSPAN code a partial
update is done, preventing the use of the helper function.
Before this change the handling of ERSPAN traffic in GRE tunnels
would cause a kernel panic when the kernel is compiled with
GCC 15+ and having FORTIFY_SOURCE configured:
memcpy: detected buffer overflow: 4 byte write of buffer size 0
Call Trace:
<IRQ>
__fortify_panic+0xd/0xf
erspan_rcv.cold+0x68/0x83
? ip_route_input_slow+0x816/0x9d0
gre_rcv+0x1b2/0x1c0
gre_rcv+0x8e/0x100
? raw_v4_input+0x2a0/0x2b0
ip_protocol_deliver_rcu+0x1ea/0x210
ip_local_deliver_finish+0x86/0x110
ip_local_deliver+0x65/0x110
? ip_rcv_finish_core+0xd6/0x360
ip_rcv+0x186/0x1a0
Reported-at: https://launchpad.net/bugs/2129580 |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: avoid deadlock on fallback while reinjecting
Jakub reported an MPTCP deadlock at fallback time:
WARNING: possible recursive locking detected
6.18.0-rc7-virtme #1 Not tainted
--------------------------------------------
mptcp_connect/20858 is trying to acquire lock:
ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280
but task is already holding lock:
ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&msk->fallback_lock);
lock(&msk->fallback_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by mptcp_connect/20858:
#0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0
#1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0
#2: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0
stack backtrace:
CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full)
Hardware name: Bochs, BIOS Bochs 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xa0
print_deadlock_bug.cold+0xc0/0xcd
validate_chain+0x2ff/0x5f0
__lock_acquire+0x34c/0x740
lock_acquire.part.0+0xbc/0x260
_raw_spin_lock_bh+0x38/0x50
__mptcp_try_fallback+0xd8/0x280
mptcp_sendmsg_frag+0x16c2/0x3050
__mptcp_retrans+0x421/0xaa0
mptcp_release_cb+0x5aa/0xa70
release_sock+0xab/0x1d0
mptcp_sendmsg+0xd5b/0x1bc0
sock_write_iter+0x281/0x4d0
new_sync_write+0x3c5/0x6f0
vfs_write+0x65e/0xbb0
ksys_write+0x17e/0x200
do_syscall_64+0xbb/0xfd0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7fa5627cbc5e
Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa
RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e
RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005
RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920
R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c
The packet scheduler could attempt a reinjection after receiving an
MP_FAIL and before the infinite map has been transmitted, causing a
deadlock since MPTCP needs to do the reinjection atomically from WRT
fallback.
Address the issue explicitly avoiding the reinjection in the critical
scenario. Note that this is the only fallback critical section that
could potentially send packets and hit the double-lock. |
| In the Linux kernel, the following vulnerability has been resolved:
net: hns3: add VLAN id validation before using
Currently, the VLAN id may be used without validation when
receive a VLAN configuration mailbox from VF. The length of
vlan_del_fail_bmap is BITS_TO_LONGS(VLAN_N_VID). It may cause
out-of-bounds memory access once the VLAN id is bigger than
or equal to VLAN_N_VID.
Therefore, VLAN id needs to be checked to ensure it is within
the range of VLAN_N_VID. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtlwifi: 8192cu: fix tid out of range in rtl92cu_tx_fill_desc()
TID getting from ieee80211_get_tid() might be out of range of array size
of sta_entry->tids[], so check TID is less than MAX_TID_COUNT. Othwerwise,
UBSAN warn:
UBSAN: array-index-out-of-bounds in drivers/net/wireless/realtek/rtlwifi/rtl8192cu/trx.c:514:30
index 10 is out of range for type 'rtl_tid_data [9]' |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/oa: Fix potential UAF in xe_oa_add_config_ioctl()
In xe_oa_add_config_ioctl(), we accessed oa_config->id after dropping
metrics_lock. Since this lock protects the lifetime of oa_config, an
attacker could guess the id and call xe_oa_remove_config_ioctl() with
perfect timing, freeing oa_config before we dereference it, leading to
a potential use-after-free.
Fix this by caching the id in a local variable while holding the lock.
v2: (Matt A)
- Dropped mutex_unlock(&oa->metrics_lock) ordering change from
xe_oa_remove_config_ioctl()
(cherry picked from commit 28aeaed130e8e587fd1b73b6d66ca41ccc5a1a31) |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/64s/slb: Fix SLB multihit issue during SLB preload
On systems using the hash MMU, there is a software SLB preload cache that
mirrors the entries loaded into the hardware SLB buffer. This preload
cache is subject to periodic eviction — typically after every 256 context
switches — to remove old entry.
To optimize performance, the kernel skips switch_mmu_context() in
switch_mm_irqs_off() when the prev and next mm_struct are the same.
However, on hash MMU systems, this can lead to inconsistencies between
the hardware SLB and the software preload cache.
If an SLB entry for a process is evicted from the software cache on one
CPU, and the same process later runs on another CPU without executing
switch_mmu_context(), the hardware SLB may retain stale entries. If the
kernel then attempts to reload that entry, it can trigger an SLB
multi-hit error.
The following timeline shows how stale SLB entries are created and can
cause a multi-hit error when a process moves between CPUs without a
MMU context switch.
CPU 0 CPU 1
----- -----
Process P
exec swapper/1
load_elf_binary
begin_new_exc
activate_mm
switch_mm_irqs_off
switch_mmu_context
switch_slb
/*
* This invalidates all
* the entries in the HW
* and setup the new HW
* SLB entries as per the
* preload cache.
*/
context_switch
sched_migrate_task migrates process P to cpu-1
Process swapper/0 context switch (to process P)
(uses mm_struct of Process P) switch_mm_irqs_off()
switch_slb
load_slb++
/*
* load_slb becomes 0 here
* and we evict an entry from
* the preload cache with
* preload_age(). We still
* keep HW SLB and preload
* cache in sync, that is
* because all HW SLB entries
* anyways gets evicted in
* switch_slb during SLBIA.
* We then only add those
* entries back in HW SLB,
* which are currently
* present in preload_cache
* (after eviction).
*/
load_elf_binary continues...
setup_new_exec()
slb_setup_new_exec()
sched_switch event
sched_migrate_task migrates
process P to cpu-0
context_switch from swapper/0 to Process P
switch_mm_irqs_off()
/*
* Since both prev and next mm struct are same we don't call
* switch_mmu_context(). This will cause the HW SLB and SW preload
* cache to go out of sync in preload_new_slb_context. Because there
* was an SLB entry which was evicted from both HW and preload cache
* on cpu-1. Now later in preload_new_slb_context(), when we will try
* to add the same preload entry again, we will add this to the SW
* preload cache and then will add it to the HW SLB. Since on cpu-0
* this entry was never invalidated, hence adding this entry to the HW
* SLB will cause a SLB multi-hit error.
*/
load_elf_binary cont
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
Input: alps - fix use-after-free bugs caused by dev3_register_work
The dev3_register_work delayed work item is initialized within
alps_reconnect() and scheduled upon receipt of the first bare
PS/2 packet from an external PS/2 device connected to the ALPS
touchpad. During device detachment, the original implementation
calls flush_workqueue() in psmouse_disconnect() to ensure
completion of dev3_register_work. However, the flush_workqueue()
in psmouse_disconnect() only blocks and waits for work items that
were already queued to the workqueue prior to its invocation. Any
work items submitted after flush_workqueue() is called are not
included in the set of tasks that the flush operation awaits.
This means that after flush_workqueue() has finished executing,
the dev3_register_work could still be scheduled. Although the
psmouse state is set to PSMOUSE_CMD_MODE in psmouse_disconnect(),
the scheduling of dev3_register_work remains unaffected.
The race condition can occur as follows:
CPU 0 (cleanup path) | CPU 1 (delayed work)
psmouse_disconnect() |
psmouse_set_state() |
flush_workqueue() | alps_report_bare_ps2_packet()
alps_disconnect() | psmouse_queue_work()
kfree(priv); // FREE | alps_register_bare_ps2_mouse()
| priv = container_of(work...); // USE
| priv->dev3 // USE
Add disable_delayed_work_sync() in alps_disconnect() to ensure
that dev3_register_work is properly canceled and prevented from
executing after the alps_data structure has been deallocated.
This bug is identified by static analysis. |
