| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: at_hdmac: fix device leak on of_dma_xlate()
Make sure to drop the reference taken when looking up the DMA platform
device during of_dma_xlate() when releasing channel resources.
Note that commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing
put_device() call in at_dma_xlate()") fixed the leak in a couple of
error paths but the reference is still leaking on successful allocation. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix string copying in parse_apply_sb_mount_options()
strscpy_pad() can't be used to copy a non-NUL-term string into a NUL-term
string of possibly bigger size. Commit 0efc5990bca5 ("string.h: Introduce
memtostr() and memtostr_pad()") provides additional information in that
regard. So if this happens, the following warning is observed:
strnlen: detected buffer overflow: 65 byte read of buffer size 64
WARNING: CPU: 0 PID: 28655 at lib/string_helpers.c:1032 __fortify_report+0x96/0xc0 lib/string_helpers.c:1032
Modules linked in:
CPU: 0 UID: 0 PID: 28655 Comm: syz-executor.3 Not tainted 6.12.54-syzkaller-00144-g5f0270f1ba00 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__fortify_report+0x96/0xc0 lib/string_helpers.c:1032
Call Trace:
<TASK>
__fortify_panic+0x1f/0x30 lib/string_helpers.c:1039
strnlen include/linux/fortify-string.h:235 [inline]
sized_strscpy include/linux/fortify-string.h:309 [inline]
parse_apply_sb_mount_options fs/ext4/super.c:2504 [inline]
__ext4_fill_super fs/ext4/super.c:5261 [inline]
ext4_fill_super+0x3c35/0xad00 fs/ext4/super.c:5706
get_tree_bdev_flags+0x387/0x620 fs/super.c:1636
vfs_get_tree+0x93/0x380 fs/super.c:1814
do_new_mount fs/namespace.c:3553 [inline]
path_mount+0x6ae/0x1f70 fs/namespace.c:3880
do_mount fs/namespace.c:3893 [inline]
__do_sys_mount fs/namespace.c:4103 [inline]
__se_sys_mount fs/namespace.c:4080 [inline]
__x64_sys_mount+0x280/0x300 fs/namespace.c:4080
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x64/0x140 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Since userspace is expected to provide s_mount_opts field to be at most 63
characters long with the ending byte being NUL-term, use a 64-byte buffer
which matches the size of s_mount_opts, so that strscpy_pad() does its job
properly. Return with error if the user still managed to provide a
non-NUL-term string here.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller. |
| In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix the crash issue for zero copy XDP_TX action
There is a crash issue when running zero copy XDP_TX action, the crash
log is shown below.
[ 216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000
[ 216.187524] Internal error: Oops: 0000000096000144 [#1] SMP
[ 216.301694] Call trace:
[ 216.304130] dcache_clean_poc+0x20/0x38 (P)
[ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0
[ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400
[ 216.317701] __stmmac_xdp_run_prog+0x164/0x368
[ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00
[ 216.326576] __napi_poll+0x40/0x218
[ 216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt
For XDP_TX action, the xdp_buff is converted to xdp_frame by
xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame
depends on the memory type of the xdp_buff. For page pool based xdp_buff
it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy
XSK pool based xdp_buff it produces xdp_frame with memory type
MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the
memory type and always uses the page pool type, this leads to invalid
mappings and causes the crash. Therefore, check the xdp_buff memory type
in stmmac_xdp_xmit_back() to fix this issue. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Do not let BPF test infra emit invalid GSO types to stack
Yinhao et al. reported that their fuzzer tool was able to trigger a
skb_warn_bad_offload() from netif_skb_features() -> gso_features_check().
When a BPF program - triggered via BPF test infra - pushes the packet
to the loopback device via bpf_clone_redirect() then mentioned offload
warning can be seen. GSO-related features are then rightfully disabled.
We get into this situation due to convert___skb_to_skb() setting
gso_segs and gso_size but not gso_type. Technically, it makes sense
that this warning triggers since the GSO properties are malformed due
to the gso_type. Potentially, the gso_type could be marked non-trustworthy
through setting it at least to SKB_GSO_DODGY without any other specific
assumptions, but that also feels wrong given we should not go further
into the GSO engine in the first place.
The checks were added in 121d57af308d ("gso: validate gso_type in GSO
handlers") because there were malicious (syzbot) senders that combine
a protocol with a non-matching gso_type. If we would want to drop such
packets, gso_features_check() currently only returns feature flags via
netif_skb_features(), so one location for potentially dropping such skbs
could be validate_xmit_unreadable_skb(), but then otoh it would be
an additional check in the fast-path for a very corner case. Given
bpf_clone_redirect() is the only place where BPF test infra could emit
such packets, lets reject them right there. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/vmscape: Add conditional IBPB mitigation
VMSCAPE is a vulnerability that exploits insufficient branch predictor
isolation between a guest and a userspace hypervisor (like QEMU). Existing
mitigations already protect kernel/KVM from a malicious guest. Userspace
can additionally be protected by flushing the branch predictors after a
VMexit.
Since it is the userspace that consumes the poisoned branch predictors,
conditionally issue an IBPB after a VMexit and before returning to
userspace. Workloads that frequently switch between hypervisor and
userspace will incur the most overhead from the new IBPB.
This new IBPB is not integrated with the existing IBPB sites. For
instance, a task can use the existing speculation control prctl() to
get an IBPB at context switch time. With this implementation, the
IBPB is doubled up: one at context switch and another before running
userspace.
The intent is to integrate and optimize these cases post-embargo.
[ dhansen: elaborate on suboptimal IBPB solution ] |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().
syzbot reported the splat below where a socket had tcp_sk(sk)->fastopen_rsk
in the TCP_ESTABLISHED state. [0]
syzbot reused the server-side TCP Fast Open socket as a new client before
the TFO socket completes 3WHS:
1. accept()
2. connect(AF_UNSPEC)
3. connect() to another destination
As of accept(), sk->sk_state is TCP_SYN_RECV, and tcp_disconnect() changes
it to TCP_CLOSE and makes connect() possible, which restarts timers.
Since tcp_disconnect() forgot to clear tcp_sk(sk)->fastopen_rsk, the
retransmit timer triggered the warning and the intended packet was not
retransmitted.
Let's call reqsk_fastopen_remove() in tcp_disconnect().
[0]:
WARNING: CPU: 2 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))
Modules linked in:
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7))
Code: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e
RSP: 0018:ffffc900002f8d40 EFLAGS: 00010293
RAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017
RDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400
RBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8
R10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540
R13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0
FS: 0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0
Call Trace:
<IRQ>
tcp_write_timer (net/ipv4/tcp_timer.c:738)
call_timer_fn (kernel/time/timer.c:1747)
__run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2372)
timer_expire_remote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135)
tmigr_handle_remote_up (kernel/time/timer_migration.c:944 kernel/time/timer_migration.c:1035)
__walk_groups.isra.0 (kernel/time/timer_migration.c:533 (discriminator 1))
tmigr_handle_remote (kernel/time/timer_migration.c:1096)
handle_softirqs (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580)
irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35))
</IRQ> |
| In the Linux kernel, the following vulnerability has been resolved:
cgroup: split cgroup_destroy_wq into 3 workqueues
A hung task can occur during [1] LTP cgroup testing when repeatedly
mounting/unmounting perf_event and net_prio controllers with
systemd.unified_cgroup_hierarchy=1. The hang manifests in
cgroup_lock_and_drain_offline() during root destruction.
Related case:
cgroup_fj_function_perf_event cgroup_fj_function.sh perf_event
cgroup_fj_function_net_prio cgroup_fj_function.sh net_prio
Call Trace:
cgroup_lock_and_drain_offline+0x14c/0x1e8
cgroup_destroy_root+0x3c/0x2c0
css_free_rwork_fn+0x248/0x338
process_one_work+0x16c/0x3b8
worker_thread+0x22c/0x3b0
kthread+0xec/0x100
ret_from_fork+0x10/0x20
Root Cause:
CPU0 CPU1
mount perf_event umount net_prio
cgroup1_get_tree cgroup_kill_sb
rebind_subsystems // root destruction enqueues
// cgroup_destroy_wq
// kill all perf_event css
// one perf_event css A is dying
// css A offline enqueues cgroup_destroy_wq
// root destruction will be executed first
css_free_rwork_fn
cgroup_destroy_root
cgroup_lock_and_drain_offline
// some perf descendants are dying
// cgroup_destroy_wq max_active = 1
// waiting for css A to die
Problem scenario:
1. CPU0 mounts perf_event (rebind_subsystems)
2. CPU1 unmounts net_prio (cgroup_kill_sb), queuing root destruction work
3. A dying perf_event CSS gets queued for offline after root destruction
4. Root destruction waits for offline completion, but offline work is
blocked behind root destruction in cgroup_destroy_wq (max_active=1)
Solution:
Split cgroup_destroy_wq into three dedicated workqueues:
cgroup_offline_wq – Handles CSS offline operations
cgroup_release_wq – Manages resource release
cgroup_free_wq – Performs final memory deallocation
This separation eliminates blocking in the CSS free path while waiting for
offline operations to complete.
[1] https://github.com/linux-test-project/ltp/blob/master/runtest/controllers |
| 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:
rcu/nocb: Fix possible invalid rdp's->nocb_cb_kthread pointer access
In the preparation stage of CPU online, if the corresponding
the rdp's->nocb_cb_kthread does not exist, will be created,
there is a situation where the rdp's rcuop kthreads creation fails,
and then de-offload this CPU's rdp, does not assign this CPU's
rdp->nocb_cb_kthread pointer, but this rdp's->nocb_gp_rdp and
rdp's->rdp_gp->nocb_gp_kthread is still valid.
This will cause the subsequent re-offload operation of this offline
CPU, which will pass the conditional check and the kthread_unpark()
will access invalid rdp's->nocb_cb_kthread pointer.
This commit therefore use rdp's->nocb_gp_kthread instead of
rdp_gp's->nocb_gp_kthread for safety check. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject narrower access to pointer ctx fields
The following BPF program, simplified from a syzkaller repro, causes a
kernel warning:
r0 = *(u8 *)(r1 + 169);
exit;
With pointer field sk being at offset 168 in __sk_buff. This access is
detected as a narrower read in bpf_skb_is_valid_access because it
doesn't match offsetof(struct __sk_buff, sk). It is therefore allowed
and later proceeds to bpf_convert_ctx_access. Note that for the
"is_narrower_load" case in the convert_ctx_accesses(), the insn->off
is aligned, so the cnt may not be 0 because it matches the
offsetof(struct __sk_buff, sk) in the bpf_convert_ctx_access. However,
the target_size stays 0 and the verifier errors with a kernel warning:
verifier bug: error during ctx access conversion(1)
This patch fixes that to return a proper "invalid bpf_context access
off=X size=Y" error on the load instruction.
The same issue affects multiple other fields in context structures that
allow narrow access. Some other non-affected fields (for sk_msg,
sk_lookup, and sockopt) were also changed to use bpf_ctx_range_ptr for
consistency.
Note this syzkaller crash was reported in the "Closes" link below, which
used to be about a different bug, fixed in
commit fce7bd8e385a ("bpf/verifier: Handle BPF_LOAD_ACQ instructions
in insn_def_regno()"). Because syzbot somehow confused the two bugs,
the new crash and repro didn't get reported to the mailing list. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix crash in icl_update_topdown_event()
The perf_fuzzer found a hard-lockup crash on a RaptorLake machine:
Oops: general protection fault, maybe for address 0xffff89aeceab400: 0000
CPU: 23 UID: 0 PID: 0 Comm: swapper/23
Tainted: [W]=WARN
Hardware name: Dell Inc. Precision 9660/0VJ762
RIP: 0010:native_read_pmc+0x7/0x40
Code: cc e8 8d a9 01 00 48 89 03 5b cd cc cc cc cc 0f 1f ...
RSP: 000:fffb03100273de8 EFLAGS: 00010046
....
Call Trace:
<TASK>
icl_update_topdown_event+0x165/0x190
? ktime_get+0x38/0xd0
intel_pmu_read_event+0xf9/0x210
__perf_event_read+0xf9/0x210
CPUs 16-23 are E-core CPUs that don't support the perf metrics feature.
The icl_update_topdown_event() should not be invoked on these CPUs.
It's a regression of commit:
f9bdf1f95339 ("perf/x86/intel: Avoid disable PMU if !cpuc->enabled in sample read")
The bug introduced by that commit is that the is_topdown_event() function
is mistakenly used to replace the is_topdown_count() call to check if the
topdown functions for the perf metrics feature should be invoked.
Fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Eliminate window where TLB flushes may be inadvertently skipped
tl;dr: There is a window in the mm switching code where the new CR3 is
set and the CPU should be getting TLB flushes for the new mm. But
should_flush_tlb() has a bug and suppresses the flush. Fix it by
widening the window where should_flush_tlb() sends an IPI.
Long Version:
=== History ===
There were a few things leading up to this.
First, updating mm_cpumask() was observed to be too expensive, so it was
made lazier. But being lazy caused too many unnecessary IPIs to CPUs
due to the now-lazy mm_cpumask(). So code was added to cull
mm_cpumask() periodically[2]. But that culling was a bit too aggressive
and skipped sending TLB flushes to CPUs that need them. So here we are
again.
=== Problem ===
The too-aggressive code in should_flush_tlb() strikes in this window:
// Turn on IPIs for this CPU/mm combination, but only
// if should_flush_tlb() agrees:
cpumask_set_cpu(cpu, mm_cpumask(next));
next_tlb_gen = atomic64_read(&next->context.tlb_gen);
choose_new_asid(next, next_tlb_gen, &new_asid, &need_flush);
load_new_mm_cr3(need_flush);
// ^ After 'need_flush' is set to false, IPIs *MUST*
// be sent to this CPU and not be ignored.
this_cpu_write(cpu_tlbstate.loaded_mm, next);
// ^ Not until this point does should_flush_tlb()
// become true!
should_flush_tlb() will suppress TLB flushes between load_new_mm_cr3()
and writing to 'loaded_mm', which is a window where they should not be
suppressed. Whoops.
=== Solution ===
Thankfully, the fuzzy "just about to write CR3" window is already marked
with loaded_mm==LOADED_MM_SWITCHING. Simply checking for that state in
should_flush_tlb() is sufficient to ensure that the CPU is targeted with
an IPI.
This will cause more TLB flush IPIs. But the window is relatively small
and I do not expect this to cause any kind of measurable performance
impact.
Update the comment where LOADED_MM_SWITCHING is written since it grew
yet another user.
Peter Z also raised a concern that should_flush_tlb() might not observe
'loaded_mm' and 'is_lazy' in the same order that switch_mm_irqs_off()
writes them. Add a barrier to ensure that they are observed in the
order they are written. |
| In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: mtk-star-emac: fix spinlock recursion issues on rx/tx poll
Use spin_lock_irqsave and spin_unlock_irqrestore instead of spin_lock
and spin_unlock in mtk_star_emac driver to avoid spinlock recursion
occurrence that can happen when enabling the DMA interrupts again in
rx/tx poll.
```
BUG: spinlock recursion on CPU#0, swapper/0/0
lock: 0xffff00000db9cf20, .magic: dead4ead, .owner: swapper/0/0,
.owner_cpu: 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted
6.15.0-rc2-next-20250417-00001-gf6a27738686c-dirty #28 PREEMPT
Hardware name: MediaTek MT8365 Open Platform EVK (DT)
Call trace:
show_stack+0x18/0x24 (C)
dump_stack_lvl+0x60/0x80
dump_stack+0x18/0x24
spin_dump+0x78/0x88
do_raw_spin_lock+0x11c/0x120
_raw_spin_lock+0x20/0x2c
mtk_star_handle_irq+0xc0/0x22c [mtk_star_emac]
__handle_irq_event_percpu+0x48/0x140
handle_irq_event+0x4c/0xb0
handle_fasteoi_irq+0xa0/0x1bc
handle_irq_desc+0x34/0x58
generic_handle_domain_irq+0x1c/0x28
gic_handle_irq+0x4c/0x120
do_interrupt_handler+0x50/0x84
el1_interrupt+0x34/0x68
el1h_64_irq_handler+0x18/0x24
el1h_64_irq+0x6c/0x70
regmap_mmio_read32le+0xc/0x20 (P)
_regmap_bus_reg_read+0x6c/0xac
_regmap_read+0x60/0xdc
regmap_read+0x4c/0x80
mtk_star_rx_poll+0x2f4/0x39c [mtk_star_emac]
__napi_poll+0x38/0x188
net_rx_action+0x164/0x2c0
handle_softirqs+0x100/0x244
__do_softirq+0x14/0x20
____do_softirq+0x10/0x20
call_on_irq_stack+0x24/0x64
do_softirq_own_stack+0x1c/0x40
__irq_exit_rcu+0xd4/0x10c
irq_exit_rcu+0x10/0x1c
el1_interrupt+0x38/0x68
el1h_64_irq_handler+0x18/0x24
el1h_64_irq+0x6c/0x70
cpuidle_enter_state+0xac/0x320 (P)
cpuidle_enter+0x38/0x50
do_idle+0x1e4/0x260
cpu_startup_entry+0x34/0x3c
rest_init+0xdc/0xe0
console_on_rootfs+0x0/0x6c
__primary_switched+0x88/0x90
``` |
| In sshd in OpenSSH before 10.0, the DisableForwarding directive does not adhere to the documentation stating that it disables X11 and agent forwarding. |
| In the Linux kernel, the following vulnerability has been resolved:
net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.
SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to
br_ioctl_call(), which causes unnecessary RTNL dance and the splat
below [0] under RTNL pressure.
Let's say Thread A is trying to detach a device from a bridge and
Thread B is trying to remove the bridge.
In dev_ioctl(), Thread A bumps the bridge device's refcnt by
netdev_hold() and releases RTNL because the following br_ioctl_call()
also re-acquires RTNL.
In the race window, Thread B could acquire RTNL and try to remove
the bridge device. Then, rtnl_unlock() by Thread B will release RTNL
and wait for netdev_put() by Thread A.
Thread A, however, must hold RTNL after the unlock in dev_ifsioc(),
which may take long under RTNL pressure, resulting in the splat by
Thread B.
Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR)
---------------------- ----------------------
sock_ioctl sock_ioctl
`- sock_do_ioctl `- br_ioctl_call
`- dev_ioctl `- br_ioctl_stub
|- rtnl_lock |
|- dev_ifsioc '
' |- dev = __dev_get_by_name(...)
|- netdev_hold(dev, ...) .
/ |- rtnl_unlock ------. |
| |- br_ioctl_call `---> |- rtnl_lock
Race | | `- br_ioctl_stub |- br_del_bridge
Window | | | |- dev = __dev_get_by_name(...)
| | | May take long | `- br_dev_delete(dev, ...)
| | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...)
| | | | `- rtnl_unlock
\ | |- rtnl_lock <-' `- netdev_run_todo
| |- ... `- netdev_run_todo
| `- rtnl_unlock |- __rtnl_unlock
| |- netdev_wait_allrefs_any
|- netdev_put(dev, ...) <----------------'
Wait refcnt decrement
and log splat below
To avoid blocking SIOCBRDELBR unnecessarily, let's not call
dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF.
In the dev_ioctl() path, we do the following:
1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl()
2. Check CAP_NET_ADMIN in dev_ioctl()
3. Call dev_load() in dev_ioctl()
4. Fetch the master dev from ifr.ifr_name in dev_ifsioc()
3. can be done by request_module() in br_ioctl_call(), so we move
1., 2., and 4. to br_ioctl_stub().
Note that 2. is also checked later in add_del_if(), but it's better
performed before RTNL.
SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since
the pre-git era, and there seems to be no specific reason to process
them there.
[0]:
unregister_netdevice: waiting for wpan3 to become free. Usage count = 2
ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at
__netdev_tracker_alloc include/linux/netdevice.h:4282 [inline]
netdev_hold include/linux/netdevice.h:4311 [inline]
dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624
dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826
sock_do_ioctl+0x1ca/0x260 net/socket.c:1213
sock_ioctl+0x23a/0x6c0 net/socket.c:1318
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: brcmstb: Fix error path after a call to regulator_bulk_get()
If the regulator_bulk_get() returns an error and no regulators
are created, we need to set their number to zero.
If we don't do this and the PCIe link up fails, a call to the
regulator_bulk_free() will result in a kernel panic.
While at it, print the error value, as we cannot return an error
upwards as the kernel will WARN() on an error from add_bus().
[kwilczynski: commit log, use comma in the message to match style with
other similar messages] |
| In the Linux kernel, the following vulnerability has been resolved:
x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()
If track_pfn_copy() fails, we already added the dst VMA to the maple
tree. As fork() fails, we'll cleanup the maple tree, and stumble over
the dst VMA for which we neither performed any reservation nor copied
any page tables.
Consequently untrack_pfn() will see VM_PAT and try obtaining the
PAT information from the page table -- which fails because the page
table was not copied.
The easiest fix would be to simply clear the VM_PAT flag of the dst VMA
if track_pfn_copy() fails. However, the whole thing is about "simply"
clearing the VM_PAT flag is shaky as well: if we passed track_pfn_copy()
and performed a reservation, but copying the page tables fails, we'll
simply clear the VM_PAT flag, not properly undoing the reservation ...
which is also wrong.
So let's fix it properly: set the VM_PAT flag only if the reservation
succeeded (leaving it clear initially), and undo the reservation if
anything goes wrong while copying the page tables: clearing the VM_PAT
flag after undoing the reservation.
Note that any copied page table entries will get zapped when the VMA will
get removed later, after copy_page_range() succeeded; as VM_PAT is not set
then, we won't try cleaning VM_PAT up once more and untrack_pfn() will be
happy. Note that leaving these page tables in place without a reservation
is not a problem, as we are aborting fork(); this process will never run.
A reproducer can trigger this usually at the first try:
https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/reproducers/pat_fork.c
WARNING: CPU: 26 PID: 11650 at arch/x86/mm/pat/memtype.c:983 get_pat_info+0xf6/0x110
Modules linked in: ...
CPU: 26 UID: 0 PID: 11650 Comm: repro3 Not tainted 6.12.0-rc5+ #92
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:get_pat_info+0xf6/0x110
...
Call Trace:
<TASK>
...
untrack_pfn+0x52/0x110
unmap_single_vma+0xa6/0xe0
unmap_vmas+0x105/0x1f0
exit_mmap+0xf6/0x460
__mmput+0x4b/0x120
copy_process+0x1bf6/0x2aa0
kernel_clone+0xab/0x440
__do_sys_clone+0x66/0x90
do_syscall_64+0x95/0x180
Likely this case was missed in:
d155df53f310 ("x86/mm/pat: clear VM_PAT if copy_p4d_range failed")
... and instead of undoing the reservation we simply cleared the VM_PAT flag.
Keep the documentation of these functions in include/linux/pgtable.h,
one place is more than sufficient -- we should clean that up for the other
functions like track_pfn_remap/untrack_pfn separately. |
| In the Linux kernel, the following vulnerability has been resolved:
net: gso: fix ownership in __udp_gso_segment
In __udp_gso_segment the skb destructor is removed before segmenting the
skb but the socket reference is kept as-is. This is an issue if the
original skb is later orphaned as we can hit the following bug:
kernel BUG at ./include/linux/skbuff.h:3312! (skb_orphan)
RIP: 0010:ip_rcv_core+0x8b2/0xca0
Call Trace:
ip_rcv+0xab/0x6e0
__netif_receive_skb_one_core+0x168/0x1b0
process_backlog+0x384/0x1100
__napi_poll.constprop.0+0xa1/0x370
net_rx_action+0x925/0xe50
The above can happen following a sequence of events when using
OpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an
OVS_ACTION_ATTR_OUTPUT action:
1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb
goes through queue_gso_packets and then __udp_gso_segment, where its
destructor is removed.
2. The segments' data are copied and sent to userspace.
3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the
same original skb is sent to its path.
4. If it later hits skb_orphan, we hit the bug.
Fix this by also removing the reference to the socket in
__udp_gso_segment. |
| In the Linux kernel, the following vulnerability has been resolved:
llc: do not use skb_get() before dev_queue_xmit()
syzbot is able to crash hosts [1], using llc and devices
not supporting IFF_TX_SKB_SHARING.
In this case, e1000 driver calls eth_skb_pad(), while
the skb is shared.
Simply replace skb_get() by skb_clone() in net/llc/llc_s_ac.c
Note that e1000 driver might have an issue with pktgen,
because it does not clear IFF_TX_SKB_SHARING, this is an
orthogonal change.
We need to audit other skb_get() uses in net/llc.
[1]
kernel BUG at net/core/skbuff.c:2178 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 16371 Comm: syz.2.2764 Not tainted 6.14.0-rc4-syzkaller-00052-gac9c34d1e45a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:pskb_expand_head+0x6ce/0x1240 net/core/skbuff.c:2178
Call Trace:
<TASK>
__skb_pad+0x18a/0x610 net/core/skbuff.c:2466
__skb_put_padto include/linux/skbuff.h:3843 [inline]
skb_put_padto include/linux/skbuff.h:3862 [inline]
eth_skb_pad include/linux/etherdevice.h:656 [inline]
e1000_xmit_frame+0x2d99/0x5800 drivers/net/ethernet/intel/e1000/e1000_main.c:3128
__netdev_start_xmit include/linux/netdevice.h:5151 [inline]
netdev_start_xmit include/linux/netdevice.h:5160 [inline]
xmit_one net/core/dev.c:3806 [inline]
dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3822
sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343
__dev_xmit_skb net/core/dev.c:4045 [inline]
__dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4621
dev_queue_xmit include/linux/netdevice.h:3313 [inline]
llc_sap_action_send_test_c+0x268/0x320 net/llc/llc_s_ac.c:144
llc_exec_sap_trans_actions net/llc/llc_sap.c:153 [inline]
llc_sap_next_state net/llc/llc_sap.c:182 [inline]
llc_sap_state_process+0x239/0x510 net/llc/llc_sap.c:209
llc_ui_sendmsg+0xd0d/0x14e0 net/llc/af_llc.c:993
sock_sendmsg_nosec net/socket.c:718 [inline] |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: always handle address removal under msk socket lock
Syzkaller reported a lockdep splat in the PM control path:
WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 sock_owned_by_me include/net/sock.h:1711 [inline]
WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 msk_owned_by_me net/mptcp/protocol.h:363 [inline]
WARNING: CPU: 0 PID: 6693 at ./include/net/sock.h:1711 mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788
Modules linked in:
CPU: 0 UID: 0 PID: 6693 Comm: syz.0.205 Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:sock_owned_by_me include/net/sock.h:1711 [inline]
RIP: 0010:msk_owned_by_me net/mptcp/protocol.h:363 [inline]
RIP: 0010:mptcp_pm_nl_addr_send_ack+0x57c/0x610 net/mptcp/pm_netlink.c:788
Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ca 7b d3 f5 eb b9 e8 c3 7b d3 f5 90 0f 0b 90 e9 dd fb ff ff e8 b5 7b d3 f5 90 <0f> 0b 90 e9 3e fb ff ff 44 89 f1 80 e1 07 38 c1 0f 8c eb fb ff ff
RSP: 0000:ffffc900034f6f60 EFLAGS: 00010283
RAX: ffffffff8bee3c2b RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90004d42000 RSI: 000000000000a407 RDI: 000000000000a408
RBP: ffffc900034f7030 R08: ffffffff8bee37f6 R09: 0100000000000000
R10: dffffc0000000000 R11: ffffed100bcc62e4 R12: ffff88805e6316e0
R13: ffff88805e630c00 R14: dffffc0000000000 R15: ffff88805e630c00
FS: 00007f7e9a7e96c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fd18ff8 CR3: 0000000032c24000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
mptcp_pm_remove_addr+0x103/0x1d0 net/mptcp/pm.c:59
mptcp_pm_remove_anno_addr+0x1f4/0x2f0 net/mptcp/pm_netlink.c:1486
mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_netlink.c:1518 [inline]
mptcp_pm_nl_del_addr_doit+0x118d/0x1af0 net/mptcp/pm_netlink.c:1629
genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0xb1f/0xec0 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:733
____sys_sendmsg+0x53a/0x860 net/socket.c:2573
___sys_sendmsg net/socket.c:2627 [inline]
__sys_sendmsg+0x269/0x350 net/socket.c:2659
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7e9998cde9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7e9a7e9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7e99ba5fa0 RCX: 00007f7e9998cde9
RDX: 000000002000c094 RSI: 0000400000000000 RDI: 0000000000000007
RBP: 00007f7e99a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7e99ba5fa0 R15: 00007fff49231088
Indeed the PM can try to send a RM_ADDR over a msk without acquiring
first the msk socket lock.
The bugged code-path comes from an early optimization: when there
are no subflows, the PM should (usually) not send RM_ADDR
notifications.
The above statement is incorrect, as without locks another process
could concur
---truncated--- |
