CVE-2025-38640

CVE-2025-38640 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Disable migration in nf_hook_run_bpf(). syzbot reported that the netfilter bpf prog can be called without migration disabled in xmit path. Then the assertion in __bpf_prog_run() fails, triggering the splat below. [0] Let's use bpf_prog_run_pin_on_cpu() in nf_hook_run_bpf(). [0]: BUG: assuming non migratable context at ./include/linux/filter.h:703 in_atomic(): 0, irqs_disabled(): 0, migration_disabled() 0 pid: 5829, name: sshd-session 3 locks held by sshd-session/5829: #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x20/0x50 net/ipv4/tcp.c:1395 #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x69/0x26c0 net/ipv4/ip_output.c:470 #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: nf_hook+0xb2/0x680 include/linux/netfilter.h:241 CPU: 0 UID: 0 PID: 5829 Comm: sshd-session Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 __cant_migrate kernel/sched/core.c:8860 [inline] __cant_migrate+0x1c7/0x250 kernel/sched/core.c:8834 __bpf_prog_run include/linux/filter.h:703 [inline] bpf_prog_run include/linux/filter.h:725 [inline] nf_hook_run_bpf+0x83/0x1e0 net/netfilter/nf_bpf_link.c:20 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook+0x370/0x680 include/linux/netfilter.h:272 NF_HOOK_COND include/linux/netfilter.h:305 [inline] ip_output+0x1bc/0x2a0 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:459 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1d7d/0x26c0 net/ipv4/ip_output.c:527 __tcp_transmit_skb+0x2686/0x3e90 net/ipv4/tcp_output.c:1479 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline] tcp_write_xmit+0x1274/0x84e0 net/ipv4/tcp_output.c:2838 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3021 tcp_push+0x225/0x700 net/ipv4/tcp.c:759 tcp_sendmsg_locked+0x1870/0x42b0 net/ipv4/tcp.c:1359 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1396 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] sock_write_iter+0x4aa/0x5b0 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c7/0x1150 fs/read_write.c:686 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7d365d407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP:

Frequently asked questions

What is CVE-2025-38640?
In the Linux kernel, the following vulnerability has been resolved: bpf: Disable migration in nf_hook_run_bpf(). syzbot reported that the netfilter bpf prog can be called without migration disabled in xmit path. Then the assertion in __bpf_prog_run() fails, triggering the splat below. [0] Let's use bpf_prog_run_pin_on_cpu() in nf_hook_run_bpf(). [0]: BUG: assuming non migratable context at ./include/linux/filter.h:703 in_atomic(): 0, irqs_disabled(): 0, migration_disabled() 0 pid: 5829, name: sshd-session 3 locks held by sshd-session/5829: #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x20/0x50 net/ipv4/tcp.c:1395 #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x69/0x26c0 net/ipv4/ip_output.c:470 #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: nf_hook+0xb2/0x680 include/linux/netfilter.h:241 CPU: 0 UID: 0 PID: 5829 Comm: sshd-session Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 __cant_migrate kernel/sched/core.c:8860 [inline] __cant_migrate+0x1c7/0x250 kernel/sched/core.c:8834 __bpf_prog_run include/linux/filter.h:703 [inline] bpf_prog_run include/linux/filter.h:725 [inline] nf_hook_run_bpf+0x83/0x1e0 net/netfilter/nf_bpf_link.c:20 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook+0x370/0x680 include/linux/netfilter.h:272 NF_HOOK_COND include/linux/netfilter.h:305 [inline] ip_output+0x1bc/0x2a0 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:459 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1d7d/0x26c0 net/ipv4/ip_output.c:527 __tcp_transmit_skb+0x2686/0x3e90 net/ipv4/tcp_output.c:1479 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline] tcp_write_xmit+0x1274/0x84e0 net/ipv4/tcp_output.c:2838 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3021 tcp_push+0x225/0x700 net/ipv4/tcp.c:759 tcp_sendmsg_locked+0x1870/0x42b0 net/ipv4/tcp.c:1359 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1396 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] sock_write_iter+0x4aa/0x5b0 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c7/0x1150 fs/read_write.c:686 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7d365d407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP:
How severe is CVE-2025-38640?
CVE-2025-38640 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-38640 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-38640?
CVE-2025-38640 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-38640?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-38640 have an EU (EUVD) identifier?
Yes. CVE-2025-38640 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25562.
When was CVE-2025-38640 published?
CVE-2025-38640 was published on 2025-08-22 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Linux Linux Kernel

All CVEs affecting Linux Linux Kernel →