syzbot


KASAN: stack-out-of-bounds Read in __xfrm_dst_hash (2)

Status: upstream: reported C repro on 2025/12/20 23:50
Reported-by: syzbot+fac42f9c9205fc907ee0@syzkaller.appspotmail.com
First crash: 259d, last: 10d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: stack-out-of-bounds Read in __xfrm_dst_hash origin:lts 17 C error 2 18d 113d 0/2 upstream: reported C repro on 2026/01/31 15:19
android-5-10 KASAN: stack-out-of-bounds Read in __xfrm_dst_hash 17 1 468d 468d 0/2 auto-obsoleted due to no activity on 2025/05/12 11:45
Last patch testing requests (6)
Created Duration User Patch Repo Result
2026/05/07 20:43 12m retest repro android13-5.10-lts report log
2026/04/14 02:38 6m retest repro android13-5.10-lts report log
2026/02/10 19:21 5m retest repro android13-5.10-lts report log
2026/01/04 00:53 6m retest repro android13-5.10-lts report log
2025/12/02 11:30 38m retest repro android13-5.10-lts report log
2025/09/22 20:25 5m retest repro android13-5.10-lts report log

Sample crash report:
==================================================================
BUG: KASAN: stack-out-of-bounds in jhash2 include/linux/jhash.h:138 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm6_addr_hash net/xfrm/xfrm_hash.h:16 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:29 [inline]
BUG: KASAN: stack-out-of-bounds in __xfrm_dst_hash+0x399/0x480 net/xfrm/xfrm_hash.h:95
Read of size 4 at addr ffffc90000170b18 by task kworker/u4:0/7

CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 jhash2 include/linux/jhash.h:138 [inline]
 __xfrm6_addr_hash net/xfrm/xfrm_hash.h:16 [inline]
 __xfrm6_daddr_saddr_hash net/xfrm/xfrm_hash.h:29 [inline]
 __xfrm_dst_hash+0x399/0x480 net/xfrm/xfrm_hash.h:95
 xfrm_dst_hash net/xfrm/xfrm_state.c:63 [inline]
 xfrm_state_find+0x28c/0x28b0 net/xfrm/xfrm_state.c:1068
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2398 [inline]
 xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2443 [inline]
 xfrm_resolve_and_create_bundle+0x697/0x29f0 net/xfrm/xfrm_policy.c:2736
 xfrm_bundle_lookup net/xfrm/xfrm_policy.c:2971 [inline]
 xfrm_lookup_with_ifid+0x7ea/0x1a80 net/xfrm/xfrm_policy.c:3102
 xfrm_lookup net/xfrm/xfrm_policy.c:3194 [inline]
 xfrm_lookup_route+0x3c/0x170 net/xfrm/xfrm_policy.c:3205
 ip_route_output_flow+0x1f8/0x2f0 net/ipv4/route.c:2808
 ip_route_output_ports include/net/route.h:169 [inline]
 igmpv3_newpack+0x281/0xc80 net/ipv4/igmp.c:372
 add_grhead+0x75/0x2e0 net/ipv4/igmp.c:443
 add_grec+0x116b/0x1410 net/ipv4/igmp.c:577
 igmpv3_send_cr net/ipv4/igmp.c:714 [inline]
 igmp_ifc_timer_expire+0x89e/0xf80 net/ipv4/igmp.c:813
 call_timer_fn+0x38/0x290 kernel/time/timer.c:1450
 expire_timers kernel/time/timer.c:1495 [inline]
 __run_timers+0x650/0x9e0 kernel/time/timer.c:1789
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1802
 __do_softirq+0x255/0x563 kernel/softirq.c:309
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x60/0x80 arch/x86/kernel/irq_64.c:77
 do_softirq+0xb0/0xf0 kernel/softirq.c:358
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:194
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_bh+0x51/0x60 kernel/locking/spinlock.c:207
 spin_unlock_bh include/linux/spinlock.h:400 [inline]
 netif_addr_unlock_bh include/linux/netdevice.h:4465 [inline]
 dev_uc_del+0x2d3/0x340 net/core/dev_addr_lists.c:615
 macsec_dev_stop+0x482/0x540 drivers/net/macsec.c:3589
 __dev_close_many+0x288/0x360 net/core/dev.c:1626
 dev_close_many+0x221/0x4d0 net/core/dev.c:1651
 unregister_netdevice_many+0x45e/0x1a80 net/core/dev.c:10757
 default_device_exit_batch+0x35e/0x3c0 net/core/dev.c:11300
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x603/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298


Memory state around the buggy address:
 ffffc90000170a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90000170a80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
>ffffc90000170b00: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
                            ^
 ffffc90000170b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90000170c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/15 03:06 android13-5.10-lts 1b32327554da 6ccb967e .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: stack-out-of-bounds Read in __xfrm_dst_hash
2025/12/20 23:48 android13-5.10-lts e253c52bbdfc d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: stack-out-of-bounds Read in __xfrm_dst_hash
2025/09/08 11:07 android13-5.10-lts 48647f2c6800 d291dd2d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: stack-out-of-bounds Read in __xfrm_dst_hash
2026/05/15 02:39 android13-5.10-lts 1b32327554da 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: stack-out-of-bounds Read in __xfrm_dst_hash
* Struck through repros no longer work on HEAD.