| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
pinctrl: fix deadlock in create_pinctrl() when handling -EPROBE_DEFER
In create_pinctrl(), pinctrl_maps_mutex is acquired before calling
add_setting(). If add_setting() returns -EPROBE_DEFER, create_pinctrl()
calls pinctrl_free(). However, pinctrl_free() attempts to acquire
pinctrl_maps_mutex, which is already held by create_pinctrl(), leading to
a potential deadlock.
This patch resolves the issue by releasing pinctrl_maps_mutex before
calling pinctrl_free(), preventing the deadlock.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix overrunning reservations in ringbuf
The BPF ring buffer internally is implemented as a power-of-2 sized circular
buffer, with two logical and ever-increasing counters: consumer_pos is the
consumer counter to show which logical position the consumer consumed the
data, and producer_pos which is the producer counter denoting the amount of
data reserved by all producers.
Each time a record is reserved, the producer that "owns" the record will
successfully advance producer counter. In user space each time a record is
read, the consumer of the data advanced the consumer counter once it finished
processing. Both counters are stored in separate pages so that from user
space, the producer counter is read-only and the consumer counter is read-write.
One aspect that simplifies and thus speeds up the implementation of both
producers and consumers is how the data area is mapped twice contiguously
back-to-back in the virtual memory, allowing to not take any special measures
for samples that have to wrap around at the end of the circular buffer data
area, because the next page after the last data page would be first data page
again, and thus the sample will still appear completely contiguous in virtual
memory.
Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for
book-keeping the length and offset, and is inaccessible to the BPF program.
Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ`
for the BPF program to use. Bing-Jhong and Muhammad reported that it is however
possible to make a second allocated memory chunk overlapping with the first
chunk and as a result, the BPF program is now able to edit first chunk's
header.
For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size
of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to
bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in
[0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets
allocate a chunk B with size 0x3000. This will succeed because consumer_pos
was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask`
check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able
to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned
earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data
pages. This means that chunk B at [0x4000,0x4008] is chunk A's header.
bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then
locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk
B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong
page and could cause a crash.
Fix it by calculating the oldest pending_pos and check whether the range
from the oldest outstanding record to the newest would span beyond the ring
buffer size. If that is the case, then reject the request. We've tested with
the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh)
before/after the fix and while it seems a bit slower on some benchmarks, it
is still not significantly enough to matter. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: avoid too many retransmit packets
If a TCP socket is using TCP_USER_TIMEOUT, and the other peer
retracted its window to zero, tcp_retransmit_timer() can
retransmit a packet every two jiffies (2 ms for HZ=1000),
for about 4 minutes after TCP_USER_TIMEOUT has 'expired'.
The fix is to make sure tcp_rtx_probe0_timed_out() takes
icsk->icsk_user_timeout into account.
Before blamed commit, the socket would not timeout after
icsk->icsk_user_timeout, but would use standard exponential
backoff for the retransmits.
Also worth noting that before commit e89688e3e978 ("net: tcp:
fix unexcepted socket die when snd_wnd is 0"), the issue
would last 2 minutes instead of 4. |
| In the Linux kernel, the following vulnerability has been resolved:
net: do not leave a dangling sk pointer, when socket creation fails
It is possible to trigger a use-after-free by:
* attaching an fentry probe to __sock_release() and the probe calling the
bpf_get_socket_cookie() helper
* running traceroute -I 1.1.1.1 on a freshly booted VM
A KASAN enabled kernel will log something like below (decoded and stripped):
==================================================================
BUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
Read of size 8 at addr ffff888007110dd8 by task traceroute/299
CPU: 2 PID: 299 Comm: traceroute Tainted: G E 6.10.0-rc2+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))
print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
kasan_report (mm/kasan/report.c:603)
? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189)
__sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)
bpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092)
bpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e
bpf_trampoline_6442506592+0x47/0xaf
__sock_release (net/socket.c:652)
__sock_create (net/socket.c:1601)
...
Allocated by task 299 on cpu 2 at 78.328492s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
__kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338)
kmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007)
sk_prot_alloc (net/core/sock.c:2075)
sk_alloc (net/core/sock.c:2134)
inet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1572)
__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)
__x64_sys_socket (net/socket.c:1718)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Freed by task 299 on cpu 2 at 78.328502s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
kasan_save_free_info (mm/kasan/generic.c:582)
poison_slab_object (mm/kasan/common.c:242)
__kasan_slab_free (mm/kasan/common.c:256)
kmem_cache_free (mm/slub.c:4437 mm/slub.c:4511)
__sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208)
inet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252)
__sock_create (net/socket.c:1572)
__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)
__x64_sys_socket (net/socket.c:1718)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Fix this by clearing the struct socket reference in sk_common_release() to cover
all protocol families create functions, which may already attached the
reference to the sk object with sock_init_data(). |
| In the Linux kernel, the following vulnerability has been resolved:
vmci: prevent speculation leaks by sanitizing event in event_deliver()
Coverity spotted that event_msg is controlled by user-space,
event_msg->event_data.event is passed to event_deliver() and used
as an index without sanitization.
This change ensures that the event index is sanitized to mitigate any
possibility of speculative information leaks.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.
Only compile tested, no access to HW. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL
commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc")
includes support for __GFP_NOFAIL, but it presents a conflict with commit
dd544141b9eb ("vmalloc: back off when the current task is OOM-killed"). A
possible scenario is as follows:
process-a
__vmalloc_node_range(GFP_KERNEL | __GFP_NOFAIL)
__vmalloc_area_node()
vm_area_alloc_pages()
--> oom-killer send SIGKILL to process-a
if (fatal_signal_pending(current)) break;
--> return NULL;
To fix this, do not check fatal_signal_pending() in vm_area_alloc_pages()
if __GFP_NOFAIL set.
This issue occurred during OPLUS KASAN TEST. Below is part of the log
-> oom-killer sends signal to process
[65731.222840] [ T1308] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/apps/uid_10198,task=gs.intelligence,pid=32454,uid=10198
[65731.259685] [T32454] Call trace:
[65731.259698] [T32454] dump_backtrace+0xf4/0x118
[65731.259734] [T32454] show_stack+0x18/0x24
[65731.259756] [T32454] dump_stack_lvl+0x60/0x7c
[65731.259781] [T32454] dump_stack+0x18/0x38
[65731.259800] [T32454] mrdump_common_die+0x250/0x39c [mrdump]
[65731.259936] [T32454] ipanic_die+0x20/0x34 [mrdump]
[65731.260019] [T32454] atomic_notifier_call_chain+0xb4/0xfc
[65731.260047] [T32454] notify_die+0x114/0x198
[65731.260073] [T32454] die+0xf4/0x5b4
[65731.260098] [T32454] die_kernel_fault+0x80/0x98
[65731.260124] [T32454] __do_kernel_fault+0x160/0x2a8
[65731.260146] [T32454] do_bad_area+0x68/0x148
[65731.260174] [T32454] do_mem_abort+0x151c/0x1b34
[65731.260204] [T32454] el1_abort+0x3c/0x5c
[65731.260227] [T32454] el1h_64_sync_handler+0x54/0x90
[65731.260248] [T32454] el1h_64_sync+0x68/0x6c
[65731.260269] [T32454] z_erofs_decompress_queue+0x7f0/0x2258
--> be->decompressed_pages = kvcalloc(be->nr_pages, sizeof(struct page *), GFP_KERNEL | __GFP_NOFAIL);
kernel panic by NULL pointer dereference.
erofs assume kvmalloc with __GFP_NOFAIL never return NULL.
[65731.260293] [T32454] z_erofs_runqueue+0xf30/0x104c
[65731.260314] [T32454] z_erofs_readahead+0x4f0/0x968
[65731.260339] [T32454] read_pages+0x170/0xadc
[65731.260364] [T32454] page_cache_ra_unbounded+0x874/0xf30
[65731.260388] [T32454] page_cache_ra_order+0x24c/0x714
[65731.260411] [T32454] filemap_fault+0xbf0/0x1a74
[65731.260437] [T32454] __do_fault+0xd0/0x33c
[65731.260462] [T32454] handle_mm_fault+0xf74/0x3fe0
[65731.260486] [T32454] do_mem_abort+0x54c/0x1b34
[65731.260509] [T32454] el0_da+0x44/0x94
[65731.260531] [T32454] el0t_64_sync_handler+0x98/0xb4
[65731.260553] [T32454] el0t_64_sync+0x198/0x19c |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: fix log recovery buffer allocation for the legacy h_size fixup
Commit a70f9fe52daa ("xfs: detect and handle invalid iclog size set by
mkfs") added a fixup for incorrect h_size values used for the initial
umount record in old xfsprogs versions. Later commit 0c771b99d6c9
("xfs: clean up calculation of LR header blocks") cleaned up the log
reover buffer calculation, but stoped using the fixed up h_size value
to size the log recovery buffer, which can lead to an out of bounds
access when the incorrect h_size does not come from the old mkfs
tool, but a fuzzer.
Fix this by open coding xlog_logrec_hblks and taking the fixed h_size
into account for this calculation. |
| In the Linux kernel, the following vulnerability has been resolved:
usb-storage: alauda: Check whether the media is initialized
The member "uzonesize" of struct alauda_info will remain 0
if alauda_init_media() fails, potentially causing divide errors
in alauda_read_data() and alauda_write_lba().
- Add a member "media_initialized" to struct alauda_info.
- Change a condition in alauda_check_media() to ensure the
first initialization.
- Add an error check for the return value of alauda_init_media(). |
| In the Linux kernel, the following vulnerability has been resolved:
net: sched: sch_multiq: fix possible OOB write in multiq_tune()
q->bands will be assigned to qopt->bands to execute subsequent code logic
after kmalloc. So the old q->bands should not be used in kmalloc.
Otherwise, an out-of-bounds write will occur. |
| An issue was discovered in drivers/bluetooth/hci_ldisc.c in the Linux kernel 6.2. In hci_uart_tty_ioctl, there is a race condition between HCIUARTSETPROTO and HCIUARTGETPROTO. HCI_UART_PROTO_SET is set before hu->proto is set. A NULL pointer dereference may occur. |
| A flaw was found in the Linux kernel. Measuring usage of the shared memory does not scale with large shared memory segment counts which could lead to resource exhaustion and DoS. |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix the maximum cell name length
The kafs filesystem limits the maximum length of a cell to 256 bytes, but a
problem occurs if someone actually does that: kafs tries to create a
directory under /proc/net/afs/ with the name of the cell, but that fails
with a warning:
WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:405
because procfs limits the maximum filename length to 255.
However, the DNS limits the maximum lookup length and, by extension, the
maximum cell name, to 255 less two (length count and trailing NUL).
Fix this by limiting the maximum acceptable cellname length to 253. This
also allows us to be sure we can create the "/afs/.<cell>/" mountpoint too.
Further, split the YFS VL record cell name maximum to be the 256 allowed by
the protocol and ignore the record retrieved by YFSVL.GetCellName if it
exceeds 253. |
| In the Linux kernel, the following vulnerability has been resolved:
dm array: fix releasing a faulty array block twice in dm_array_cursor_end
When dm_bm_read_lock() fails due to locking or checksum errors, it
releases the faulty block implicitly while leaving an invalid output
pointer behind. The caller of dm_bm_read_lock() should not operate on
this invalid dm_block pointer, or it will lead to undefined result.
For example, the dm_array_cursor incorrectly caches the invalid pointer
on reading a faulty array block, causing a double release in
dm_array_cursor_end(), then hitting the BUG_ON in dm-bufio cache_put().
Reproduce steps:
1. initialize a cache device
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc $262144"
dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
2. wipe the second array block offline
dmsteup remove cache cmeta cdata corig
mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \
2>/dev/null | hexdump -e '1/8 "%u\n"')
ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \
2>/dev/null | hexdump -e '1/8 "%u\n"')
dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock
3. try reopen the cache device
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc $262144"
dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
Kernel logs:
(snip)
device-mapper: array: array_block_check failed: blocknr 0 != wanted 10
device-mapper: block manager: array validator check failed for block 10
device-mapper: array: get_ablock failed
device-mapper: cache metadata: dm_array_cursor_next for mapping failed
------------[ cut here ]------------
kernel BUG at drivers/md/dm-bufio.c:638!
Fix by setting the cached block pointer to NULL on errors.
In addition to the reproducer described above, this fix can be
verified using the "array_cursor/damaged" test in dm-unit:
dm-unit run /pdata/array_cursor/damaged --kernel-dir <KERNEL_DIR> |
| In the Linux kernel, the following vulnerability has been resolved:
net: restrict SO_REUSEPORT to inet sockets
After blamed commit, crypto sockets could accidentally be destroyed
from RCU call back, as spotted by zyzbot [1].
Trying to acquire a mutex in RCU callback is not allowed.
Restrict SO_REUSEPORT socket option to inet sockets.
v1 of this patch supported TCP, UDP and SCTP sockets,
but fcnal-test.sh test needed RAW and ICMP support.
[1]
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:562
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 24, name: ksoftirqd/1
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by ksoftirqd/1/24:
#0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2561 [inline]
#0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_core+0xa37/0x17a0 kernel/rcu/tree.c:2823
Preemption disabled at:
[<ffffffff8161c8c8>] softirq_handle_begin kernel/softirq.c:402 [inline]
[<ffffffff8161c8c8>] handle_softirqs+0x128/0x9b0 kernel/softirq.c:537
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc3-syzkaller-00174-ga024e377efed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
__might_resched+0x5d4/0x780 kernel/sched/core.c:8758
__mutex_lock_common kernel/locking/mutex.c:562 [inline]
__mutex_lock+0x131/0xee0 kernel/locking/mutex.c:735
crypto_put_default_null_skcipher+0x18/0x70 crypto/crypto_null.c:179
aead_release+0x3d/0x50 crypto/algif_aead.c:489
alg_do_release crypto/af_alg.c:118 [inline]
alg_sock_destruct+0x86/0xc0 crypto/af_alg.c:502
__sk_destruct+0x58/0x5f0 net/core/sock.c:2260
rcu_do_batch kernel/rcu/tree.c:2567 [inline]
rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
run_ksoftirqd+0xca/0x130 kernel/softirq.c:950
smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/uverbs: Prevent integer overflow issue
In the expression "cmd.wqe_size * cmd.wr_count", both variables are u32
values that come from the user so the multiplication can lead to integer
wrapping. Then we pass the result to uverbs_request_next_ptr() which also
could potentially wrap. The "cmd.sge_count * sizeof(struct ib_uverbs_sge)"
multiplication can also overflow on 32bit systems although it's fine on
64bit systems.
This patch does two things. First, I've re-arranged the condition in
uverbs_request_next_ptr() so that the use controlled variable "len" is on
one side of the comparison by itself without any math. Then I've modified
all the callers to use size_mul() for the multiplications. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: vmscan: account for free pages to prevent infinite Loop in throttle_direct_reclaim()
The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.
#0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
#1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
#2 [ffff80002cb6f990] schedule at ffff800008abc50c
#3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
#4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
#5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
#6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
#7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
#8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
#9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4
At this point, the pgdat contains the following two zones:
NODE: 4 ZONE: 0 ADDR: ffff00817fffe540 NAME: "DMA32"
SIZE: 20480 MIN/LOW/HIGH: 11/28/45
VM_STAT:
NR_FREE_PAGES: 359
NR_ZONE_INACTIVE_ANON: 18813
NR_ZONE_ACTIVE_ANON: 0
NR_ZONE_INACTIVE_FILE: 50
NR_ZONE_ACTIVE_FILE: 0
NR_ZONE_UNEVICTABLE: 0
NR_ZONE_WRITE_PENDING: 0
NR_MLOCK: 0
NR_BOUNCE: 0
NR_ZSPAGES: 0
NR_FREE_CMA_PAGES: 0
NODE: 4 ZONE: 1 ADDR: ffff00817fffec00 NAME: "Normal"
SIZE: 8454144 PRESENT: 98304 MIN/LOW/HIGH: 68/166/264
VM_STAT:
NR_FREE_PAGES: 146
NR_ZONE_INACTIVE_ANON: 94668
NR_ZONE_ACTIVE_ANON: 3
NR_ZONE_INACTIVE_FILE: 735
NR_ZONE_ACTIVE_FILE: 78
NR_ZONE_UNEVICTABLE: 0
NR_ZONE_WRITE_PENDING: 0
NR_MLOCK: 0
NR_BOUNCE: 0
NR_ZSPAGES: 0
NR_FREE_CMA_PAGES: 0
In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.
Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.
crash> p nr_swap_pages
nr_swap_pages = $1937 = {
counter = 0
}
As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.
The problem is that the pgdat->kswapd_failures hasn't been incremented.
crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
$1935 = 0x0
This is because the node deemed balanced. The node balancing logic in
balance_pgdat() evaluates all zones collectively. If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced. This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.
The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages). This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable. By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.
The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL. This issue arises from
zone_reclaimable_pages
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/dp_mst: Fix resetting msg rx state after topology removal
If the MST topology is removed during the reception of an MST down reply
or MST up request sideband message, the
drm_dp_mst_topology_mgr::up_req_recv/down_rep_recv states could be reset
from one thread via drm_dp_mst_topology_mgr_set_mst(false), racing with
the reading/parsing of the message from another thread via
drm_dp_mst_handle_down_rep() or drm_dp_mst_handle_up_req(). The race is
possible since the reader/parser doesn't hold any lock while accessing
the reception state. This in turn can lead to a memory corruption in the
reader/parser as described by commit bd2fccac61b4 ("drm/dp_mst: Fix MST
sideband message body length check").
Fix the above by resetting the message reception state if needed before
reading/parsing a message. Another solution would be to hold the
drm_dp_mst_topology_mgr::lock for the whole duration of the message
reception/parsing in drm_dp_mst_handle_down_rep() and
drm_dp_mst_handle_up_req(), however this would require a bigger change.
Since the fix is also needed for stable, opting for the simpler solution
in this patch. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/dp_mst: Ensure mst_primary pointer is valid in drm_dp_mst_handle_up_req()
While receiving an MST up request message from one thread in
drm_dp_mst_handle_up_req(), the MST topology could be removed from
another thread via drm_dp_mst_topology_mgr_set_mst(false), freeing
mst_primary and setting drm_dp_mst_topology_mgr::mst_primary to NULL.
This could lead to a NULL deref/use-after-free of mst_primary in
drm_dp_mst_handle_up_req().
Avoid the above by holding a reference for mst_primary in
drm_dp_mst_handle_up_req() while it's used.
v2: Fix kfreeing the request if getting an mst_primary reference fails. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix race between element replace and close()
Element replace (with a socket different from the one stored) may race
with socket's close() link popping & unlinking. __sock_map_delete()
unconditionally unrefs the (wrong) element:
// set map[0] = s0
map_update_elem(map, 0, s0)
// drop fd of s0
close(s0)
sock_map_close()
lock_sock(sk) (s0!)
sock_map_remove_links(sk)
link = sk_psock_link_pop()
sock_map_unlink(sk, link)
sock_map_delete_from_link
// replace map[0] with s1
map_update_elem(map, 0, s1)
sock_map_update_elem
(s1!) lock_sock(sk)
sock_map_update_common
psock = sk_psock(sk)
spin_lock(&stab->lock)
osk = stab->sks[idx]
sock_map_add_link(..., &stab->sks[idx])
sock_map_unref(osk, &stab->sks[idx])
psock = sk_psock(osk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test(&psock))
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
unlock_sock(sk)
__sock_map_delete
spin_lock(&stab->lock)
sk = *psk // s1 replaced s0; sk == s1
if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch
sk = xchg(psk, NULL)
if (sk)
sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle
psock = sk_psock(sk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test())
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
release_sock(sk)
Then close(map) enqueues bpf_map_free_deferred, which finally calls
sock_map_free(). This results in some refcount_t warnings along with
a KASAN splat [1].
Fix __sock_map_delete(), do not allow sock_map_unref() on elements that
may have been replaced.
[1]:
BUG: KASAN: slab-use-after-free in sock_map_free+0x10e/0x330
Write of size 4 at addr ffff88811f5b9100 by task kworker/u64:12/1063
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Not tainted 6.12.0+ #125
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
Call Trace:
<TASK>
dump_stack_lvl+0x68/0x90
print_report+0x174/0x4f6
kasan_report+0xb9/0x190
kasan_check_range+0x10f/0x1e0
sock_map_free+0x10e/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1202:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
__kasan_slab_alloc+0x85/0x90
kmem_cache_alloc_noprof+0x131/0x450
sk_prot_alloc+0x5b/0x220
sk_alloc+0x2c/0x870
unix_create1+0x88/0x8a0
unix_create+0xc5/0x180
__sock_create+0x241/0x650
__sys_socketpair+0x1ce/0x420
__x64_sys_socketpair+0x92/0x100
do_syscall_64+0x93/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 46:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kmem_cache_free+0x1a1/0x590
__sk_destruct+0x388/0x5a0
sk_psock_destroy+0x73e/0xa50
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
The bu
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: nl80211: fix NL80211_ATTR_MLO_LINK_ID off-by-one
Since the netlink attribute range validation provides inclusive
checking, the *max* of attribute NL80211_ATTR_MLO_LINK_ID should be
IEEE80211_MLD_MAX_NUM_LINKS - 1 otherwise causing an off-by-one.
One crash stack for demonstration:
==================================================================
BUG: KASAN: wild-memory-access in ieee80211_tx_control_port+0x3b6/0xca0 net/mac80211/tx.c:5939
Read of size 6 at addr 001102080000000c by task fuzzer.386/9508
CPU: 1 PID: 9508 Comm: syz.1.386 Not tainted 6.1.70 #2
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x177/0x231 lib/dump_stack.c:106
print_report+0xe0/0x750 mm/kasan/report.c:398
kasan_report+0x139/0x170 mm/kasan/report.c:495
kasan_check_range+0x287/0x290 mm/kasan/generic.c:189
memcpy+0x25/0x60 mm/kasan/shadow.c:65
ieee80211_tx_control_port+0x3b6/0xca0 net/mac80211/tx.c:5939
rdev_tx_control_port net/wireless/rdev-ops.h:761 [inline]
nl80211_tx_control_port+0x7b3/0xc40 net/wireless/nl80211.c:15453
genl_family_rcv_msg_doit+0x22e/0x320 net/netlink/genetlink.c:756
genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
genl_rcv_msg+0x539/0x740 net/netlink/genetlink.c:850
netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2508
genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
netlink_unicast+0x74b/0x8c0 net/netlink/af_netlink.c:1352
netlink_sendmsg+0x882/0xb90 net/netlink/af_netlink.c:1874
sock_sendmsg_nosec net/socket.c:716 [inline]
__sock_sendmsg net/socket.c:728 [inline]
____sys_sendmsg+0x5cc/0x8f0 net/socket.c:2499
___sys_sendmsg+0x21c/0x290 net/socket.c:2553
__sys_sendmsg net/socket.c:2582 [inline]
__do_sys_sendmsg net/socket.c:2591 [inline]
__se_sys_sendmsg+0x19e/0x270 net/socket.c:2589
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x45/0x90 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Update the policy to ensure correct validation. |
