In the Linux kernel, the following vulnerability has been resolved:
PCI: endpoint: Fix configfs group list head handling
Doing a list_del() on the epf_group field of struct pci_epf_driver in
pci_epf_remove_cfs() is not correct as this field is a list head, not
a list entry. This list_del() call triggers a KASAN warning when an
endpoint function driver which has a configfs attribute group is torn
down:
==================================================================
BUG: KASAN: slab-use-after-free in pci_epf_remove_cfs+0x17c/0x198
Write of size 8 at addr ffff00010f4a0d80 by task rmmod/319
CPU: 3 UID: 0 PID: 319 Comm: rmmod Not tainted 6.16.0-rc2 #1 NONE
Hardware name: Radxa ROCK 5B (DT)
Call trace:
show_stack+0x2c/0x84 (C)
dump_stack_lvl+0x70/0x98
print_report+0x17c/0x538
kasan_report+0xb8/0x190
__asan_report_store8_noabort+0x20/0x2c
pci_epf_remove_cfs+0x17c/0x198
pci_epf_unregister_driver+0x18/0x30
nvmet_pci_epf_cleanup_module+0x24/0x30 [nvmet_pci_epf]
__arm64_sys_delete_module+0x264/0x424
invoke_syscall+0x70/0x260
el0_svc_common.constprop.0+0xac/0x230
do_el0_svc+0x40/0x58
el0_svc+0x48/0xdc
el0t_64_sync_handler+0x10c/0x138
el0t_64_sync+0x198/0x19c
...
Remove this incorrect list_del() call from pci_epf_remove_cfs().
In the Linux kernel, the following vulnerability has been resolved:
soc: qcom: mdt_loader: Ensure we don't read past the ELF header
When the MDT loader is used in remoteproc, the ELF header is sanitized
beforehand, but that's not necessary the case for other clients.
Validate the size of the firmware buffer to ensure that we don't read
past the end as we iterate over the header. e_phentsize and e_shentsize
are validated as well, to ensure that the assumptions about step size in
the traversal are valid.
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: fix soft lockup in br_multicast_query_expired()
When set multicast_query_interval to a large value, the local variable
'time' in br_multicast_send_query() may overflow. If the time is smaller
than jiffies, the timer will expire immediately, and then call mod_timer()
again, which creates a loop and may trigger the following soft lockup
issue.
watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66]
CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none)
Call Trace:
<IRQ>
__netdev_alloc_skb+0x2e/0x3a0
br_ip6_multicast_alloc_query+0x212/0x1b70
__br_multicast_send_query+0x376/0xac0
br_multicast_send_query+0x299/0x510
br_multicast_query_expired.constprop.0+0x16d/0x1b0
call_timer_fn+0x3b/0x2a0
__run_timers+0x619/0x950
run_timer_softirq+0x11c/0x220
handle_softirqs+0x18e/0x560
__irq_exit_rcu+0x158/0x1a0
sysvec_apic_timer_interrupt+0x76/0x90
</IRQ>
This issue can be reproduced with:
ip link add br0 type bridge
echo 1 > /sys/class/net/br0/bridge/multicast_querier
echo 0xffffffffffffffff >
/sys/class/net/br0/bridge/multicast_query_interval
ip link set dev br0 up
The multicast_startup_query_interval can also cause this issue. Similar to
the commit 99b40610956a ("net: bridge: mcast: add and enforce query
interval minimum"), add check for the query interval maximum to fix this
issue.
In the Linux kernel, the following vulnerability has been resolved:
mm/debug_vm_pgtable: clear page table entries at destroy_args()
The mm/debug_vm_pagetable test allocates manually page table entries for
the tests it runs, using also its manually allocated mm_struct. That in
itself is ok, but when it exits, at destroy_args() it fails to clear those
entries with the *_clear functions.
The problem is that leaves stale entries. If another process allocates an
mm_struct with a pgd at the same address, it may end up running into the
stale entry. This is happening in practice on a debug kernel with
CONFIG_DEBUG_VM_PGTABLE=y, for example this is the output with some extra
debugging I added (it prints a warning trace if pgtables_bytes goes
negative, in addition to the warning at check_mm() function):
[ 2.539353] debug_vm_pgtable: [get_random_vaddr ]: random_vaddr is 0x7ea247140000
[ 2.539366] kmem_cache info
[ 2.539374] kmem_cachep 0x000000002ce82385 - freelist 0x0000000000000000 - offset 0x508
[ 2.539447] debug_vm_pgtable: [init_args ]: args->mm is 0x000000002267cc9e
(...)
[ 2.552800] WARNING: CPU: 5 PID: 116 at include/linux/mm.h:2841 free_pud_range+0x8bc/0x8d0
[ 2.552816] Modules linked in:
[ 2.552843] CPU: 5 UID: 0 PID: 116 Comm: modprobe Not tainted 6.12.0-105.debug_vm2.el10.ppc64le+debug #1 VOLUNTARY
[ 2.552859] Hardware name: IBM,9009-41A POWER9 (architected) 0x4e0202 0xf000005 of:IBM,FW910.00 (VL910_062) hv:phyp pSeries
[ 2.552872] NIP: c0000000007eef3c LR: c0000000007eef30 CTR: c0000000003d8c90
[ 2.552885] REGS: c0000000622e73b0 TRAP: 0700 Not tainted (6.12.0-105.debug_vm2.el10.ppc64le+debug)
[ 2.552899] MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24002822 XER: 0000000a
[ 2.552954] CFAR: c0000000008f03f0 IRQMASK: 0
[ 2.552954] GPR00: c0000000007eef30 c0000000622e7650 c000000002b1ac00 0000000000000001
[ 2.552954] GPR04: 0000000000000008 0000000000000000 c0000000007eef30 ffffffffffffffff
[ 2.552954] GPR08: 00000000ffff00f5 0000000000000001 0000000000000048 0000000000004000
[ 2.552954] GPR12: 00000003fa440000 c000000017ffa300 c0000000051d9f80 ffffffffffffffdb
[ 2.552954] GPR16: 0000000000000000 0000000000000008 000000000000000a 60000000000000e0
[ 2.552954] GPR20: 4080000000000000 c0000000113af038 00007fffcf130000 0000700000000000
[ 2.552954] GPR24: c000000062a6a000 0000000000000001 8000000062a68000 0000000000000001
[ 2.552954] GPR28: 000000000000000a c000000062ebc600 0000000000002000 c000000062ebc760
[ 2.553170] NIP [c0000000007eef3c] free_pud_range+0x8bc/0x8d0
[ 2.553185] LR [c0000000007eef30] free_pud_range+0x8b0/0x8d0
[ 2.553199] Call Trace:
[ 2.553207] [c0000000622e7650] [c0000000007eef30] free_pud_range+0x8b0/0x8d0 (unreliable)
[ 2.553229] [c0000000622e7750] [c0000000007f40b4] free_pgd_range+0x284/0x3b0
[ 2.553248] [c0000000622e7800] [c0000000007f4630] free_pgtables+0x450/0x570
[ 2.553274] [c0000000622e78e0] [c0000000008161c0] exit_mmap+0x250/0x650
[ 2.553292] [c0000000622e7a30] [c0000000001b95b8] __mmput+0x98/0x290
[ 2.558344] [c0000000622e7a80] [c0000000001d1018] exit_mm+0x118/0x1b0
[ 2.558361] [c0000000622e7ac0] [c0000000001d141c] do_exit+0x2ec/0x870
[ 2.558376] [c0000000622e7b60] [c0000000001d1ca8] do_group_exit+0x88/0x150
[ 2.558391] [c0000000622e7bb0] [c0000000001d1db8] sys_exit_group+0x48/0x50
[ 2.558407] [c0000000622e7be0] [c00000000003d810] system_call_exception+0x1e0/0x4c0
[ 2.558423] [c0000000622e7e50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
(...)
[ 2.558892] ---[ end trace 0000000000000000 ]---
[ 2.559022] BUG: Bad rss-counter state mm:000000002267cc9e type:MM_ANONPAGES val:1
[ 2.559037] BUG: non-zero pgtables_bytes on freeing mm: -6144
Here the modprobe process ended up with an allocated mm_struct from the
mm_struct slab that was used before by the debug_vm_pgtable test. That is
not a problem, since the mm_stru
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
net: gso: Forbid IPv6 TSO with extensions on devices with only IPV6_CSUM
When performing Generic Segmentation Offload (GSO) on an IPv6 packet that
contains extension headers, the kernel incorrectly requests checksum offload
if the egress device only advertises NETIF_F_IPV6_CSUM feature, which has
a strict contract: it supports checksum offload only for plain TCP or UDP
over IPv6 and explicitly does not support packets with extension headers.
The current GSO logic violates this contract by failing to disable the feature
for packets with extension headers, such as those used in GREoIPv6 tunnels.
This violation results in the device being asked to perform an operation
it cannot support, leading to a `skb_warn_bad_offload` warning and a collapse
of network throughput. While device TSO/USO is correctly bypassed in favor
of software GSO for these packets, the GSO stack must be explicitly told not
to request checksum offload.
Mask NETIF_F_IPV6_CSUM, NETIF_F_TSO6 and NETIF_F_GSO_UDP_L4
in gso_features_check if the IPv6 header contains extension headers to compute
checksum in software.
The exception is a BIG TCP extension, which, as stated in commit
68e068cabd2c6c53 ("net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets"):
"The feature is only enabled on devices that support BIG TCP TSO.
The header is only present for PF_PACKET taps like tcpdump,
and not transmitted by physical devices."
kernel log output (truncated):
WARNING: CPU: 1 PID: 5273 at net/core/dev.c:3535 skb_warn_bad_offload+0x81/0x140
...
Call Trace:
<TASK>
skb_checksum_help+0x12a/0x1f0
validate_xmit_skb+0x1a3/0x2d0
validate_xmit_skb_list+0x4f/0x80
sch_direct_xmit+0x1a2/0x380
__dev_xmit_skb+0x242/0x670
__dev_queue_xmit+0x3fc/0x7f0
ip6_finish_output2+0x25e/0x5d0
ip6_finish_output+0x1fc/0x3f0
ip6_tnl_xmit+0x608/0xc00 [ip6_tunnel]
ip6gre_tunnel_xmit+0x1c0/0x390 [ip6_gre]
dev_hard_start_xmit+0x63/0x1c0
__dev_queue_xmit+0x6d0/0x7f0
ip6_finish_output2+0x214/0x5d0
ip6_finish_output+0x1fc/0x3f0
ip6_xmit+0x2ca/0x6f0
ip6_finish_output+0x1fc/0x3f0
ip6_xmit+0x2ca/0x6f0
inet6_csk_xmit+0xeb/0x150
__tcp_transmit_skb+0x555/0xa80
tcp_write_xmit+0x32a/0xe90
tcp_sendmsg_locked+0x437/0x1110
tcp_sendmsg+0x2f/0x50
...
skb linear: 00000000: e4 3d 1a 7d ec 30 e4 3d 1a 7e 5d 90 86 dd 60 0e
skb linear: 00000010: 00 0a 1b 34 3c 40 20 11 00 00 00 00 00 00 00 00
skb linear: 00000020: 00 00 00 00 00 12 20 11 00 00 00 00 00 00 00 00
skb linear: 00000030: 00 00 00 00 00 11 2f 00 04 01 04 01 01 00 00 00
skb linear: 00000040: 86 dd 60 0e 00 0a 1b 00 06 40 20 23 00 00 00 00
skb linear: 00000050: 00 00 00 00 00 00 00 00 00 12 20 23 00 00 00 00
skb linear: 00000060: 00 00 00 00 00 00 00 00 00 11 bf 96 14 51 13 f9
skb linear: 00000070: ae 27 a0 a8 2b e3 80 18 00 40 5b 6f 00 00 01 01
skb linear: 00000080: 08 0a 42 d4 50 d5 4b 70 f8 1a
In the Linux kernel, the following vulnerability has been resolved:
drm/hisilicon/hibmc: fix the hibmc loaded failed bug
When hibmc loaded failed, the driver use hibmc_unload to free the
resource, but the mutexes in mode.config are not init, which will
access an NULL pointer. Just change goto statement to return, because
hibnc_hw_init() doesn't need to free anything.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit
The following setup can trigger a WARNING in htb_activate due to
the condition: !cl->leaf.q->q.qlen
tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: htb default 1
tc class add dev lo parent 1: classid 1:1 \
htb rate 64bit
tc qdisc add dev lo parent 1:1 handle f: \
cake memlimit 1b
ping -I lo -f -c1 -s64 -W0.001 127.0.0.1
This is because the low memlimit leads to a low buffer_limit, which
causes packet dropping. However, cake_enqueue still returns
NET_XMIT_SUCCESS, causing htb_enqueue to call htb_activate with an
empty child qdisc. We should return NET_XMIT_CN when packets are
dropped from the same tin and flow.
I do not believe return value of NET_XMIT_CN is necessary for packet
drops in the case of ack filtering, as that is meant to optimize
performance, not to signal congestion.
In the Linux kernel, the following vulnerability has been resolved:
fs: Prevent file descriptor table allocations exceeding INT_MAX
When sysctl_nr_open is set to a very high value (for example, 1073741816
as set by systemd), processes attempting to use file descriptors near
the limit can trigger massive memory allocation attempts that exceed
INT_MAX, resulting in a WARNING in mm/slub.c:
WARNING: CPU: 0 PID: 44 at mm/slub.c:5027 __kvmalloc_node_noprof+0x21a/0x288
This happens because kvmalloc_array() and kvmalloc() check if the
requested size exceeds INT_MAX and emit a warning when the allocation is
not flagged with __GFP_NOWARN.
Specifically, when nr_open is set to 1073741816 (0x3ffffff8) and a
process calls dup2(oldfd, 1073741880), the kernel attempts to allocate:
- File descriptor array: 1073741880 * 8 bytes = 8,589,935,040 bytes
- Multiple bitmaps: ~400MB
- Total allocation size: > 8GB (exceeding INT_MAX = 2,147,483,647)
Reproducer:
1. Set /proc/sys/fs/nr_open to 1073741816:
# echo 1073741816 > /proc/sys/fs/nr_open
2. Run a program that uses a high file descriptor:
#include <unistd.h>
#include <sys/resource.h>
int main() {
struct rlimit rlim = {1073741824, 1073741824};
setrlimit(RLIMIT_NOFILE, &rlim);
dup2(2, 1073741880); // Triggers the warning
return 0;
}
3. Observe WARNING in dmesg at mm/slub.c:5027
systemd commit a8b627a introduced automatic bumping of fs.nr_open to the
maximum possible value. The rationale was that systems with memory
control groups (memcg) no longer need separate file descriptor limits
since memory is properly accounted. However, this change overlooked
that:
1. The kernel's allocation functions still enforce INT_MAX as a maximum
size regardless of memcg accounting
2. Programs and tests that legitimately test file descriptor limits can
inadvertently trigger massive allocations
3. The resulting allocations (>8GB) are impractical and will always fail
systemd's algorithm starts with INT_MAX and keeps halving the value
until the kernel accepts it. On most systems, this results in nr_open
being set to 1073741816 (0x3ffffff8), which is just under 1GB of file
descriptors.
While processes rarely use file descriptors near this limit in normal
operation, certain selftests (like
tools/testing/selftests/core/unshare_test.c) and programs that test file
descriptor limits can trigger this issue.
Fix this by adding a check in alloc_fdtable() to ensure the requested
allocation size does not exceed INT_MAX. This causes the operation to
fail with -EMFILE instead of triggering a kernel warning and avoids the
impractical >8GB memory allocation request.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Validate UAC3 cluster segment descriptors
UAC3 class segment descriptors need to be verified whether their sizes
match with the declared lengths and whether they fit with the
allocated buffer sizes, too. Otherwise malicious firmware may lead to
the unexpected OOB accesses.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: qgroup: fix race between quota disable and quota rescan ioctl
There's a race between a task disabling quotas and another running the
rescan ioctl that can result in a use-after-free of qgroup records from
the fs_info->qgroup_tree rbtree.
This happens as follows:
1) Task A enters btrfs_ioctl_quota_rescan() -> btrfs_qgroup_rescan();
2) Task B enters btrfs_quota_disable() and calls
btrfs_qgroup_wait_for_completion(), which does nothing because at that
point fs_info->qgroup_rescan_running is false (it wasn't set yet by
task A);
3) Task B calls btrfs_free_qgroup_config() which starts freeing qgroups
from fs_info->qgroup_tree without taking the lock fs_info->qgroup_lock;
4) Task A enters qgroup_rescan_zero_tracking() which starts iterating
the fs_info->qgroup_tree tree while holding fs_info->qgroup_lock,
but task B is freeing qgroup records from that tree without holding
the lock, resulting in a use-after-free.
Fix this by taking fs_info->qgroup_lock at btrfs_free_qgroup_config().
Also at btrfs_qgroup_rescan() don't start the rescan worker if quotas
were already disabled.