CVE-2025-21718net: rose: fix timer races against user threads

Official description

In the Linux kernel, the following vulnerability has been resolved: net: rose: fix timer races against user threads Rose timers only acquire the socket spinlock, without checking if the socket is owned by one user thread. Add a check and rearm the timers if needed. BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x31d/0x360 net/rose/rose_timer.c:174 Read of size 2 at addr ffff88802f09b82a by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.13.0-rc5-syzkaller-00172-gd1bf27c4e176 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 rose_timer_expiry+0x31d/0x360 net/rose/rose_timer.c:174 call_timer_fn+0x187/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2430 run_timer_base kernel/time/timer.c:2439 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 </IRQ>

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/52f5aff33ca73b2c2fa93f40a3de308012e63cf4
• https://git.kernel.org/stable/c/0d5bca3be27bfcf8f980f2fed49b6cbb7dafe4a1
• https://git.kernel.org/stable/c/1409b45d4690308c502c6caf22f01c3c205b4717
• https://git.kernel.org/stable/c/f55c88e3ca5939a6a8a329024aed8f3d98eea8e4
• https://git.kernel.org/stable/c/51c128ba038cf1b79d605cbee325919b45ab95a5
• https://git.kernel.org/stable/c/1992fb261c90e9827cf5dc3115d89bb0853252c9
• https://git.kernel.org/stable/c/58051a284ac18a3bb815aac6289a679903ddcc3f
• https://git.kernel.org/stable/c/5de7665e0a0746b5ad7943554b34db8f8614a196
• https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
• https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html
• https://cert-portal.siemens.com/productcert/html/ssa-457936.html