KASAN: slab-use-after-free Read in nr_add

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
de3a9f54-ff8f-42f4-8033-d94866cb2a84	assessment-security	DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	KASAN: slab-use-after-free Read in nr_add_node	2026/05/31 04:07	2026/05/31 04:07	2026/05/31 05:08	6b4a844333e83556da95d61d7f207e7ef5cd4bc6
a8e6f8d9-f420-436a-aaa7-c0343b36253f	assessment-security		💥	KASAN: slab-use-after-free Read in nr_add_node	2026/05/14 14:00	2026/05/14 14:00	2026/05/14 14:01	6ccb967e465e832a7bfd7a116ad00d52a0923a5d	failed to run ["git" "pull" "origin" "HEAD" "--depth=1" "--allow-unrelated-histories"]: exit status 128 From /app/workdir/repo/linux * branch HEAD -> FETCH_HEAD Updating files: ... truncated to first 200 bytes; open job for full error

Title	Replies (including bot)	Last reply
[syzbot] Monthly hams report (Dec 2025)	0 (1)	2025/12/26 07:48
[PATCH] netrom: Prevent race conditions between multiple add route	21 (21)	2025/11/13 06:33
[syzbot] [hams?] KASAN: slab-use-after-free Read in nr_add_node	2 (7)	2025/10/19 13:55

Title

Replies (including bot)

Last reply

[syzbot] Monthly hams report (Dec 2025)

0 (1)

2025/12/26 07:48

[PATCH] netrom: Prevent race conditions between multiple add route

21 (21)

2025/11/13 06:33

[syzbot] [hams?] KASAN: slab-use-after-free Read in nr_add_node

2 (7)

2025/10/19 13:55

Kernel	Title	Rank 🛈	Repro	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.6	KASAN: slab-use-after-free Read in nr_add_node origin:upstream missing-backport	19	syz	error	1	271d	271d	0/2	upstream: reported syz repro on 2025/09/18 05:23
linux-6.1	KASAN: use-after-free Read in nr_add_node	19			1	461d	461d	0/3	auto-obsoleted due to no activity on 2025/06/19 16:48
linux-6.1	KASAN: use-after-free Read in nr_add_node (2) origin:upstream	19	C	error	1	169d	271d	0/3	upstream: reported C repro on 2025/09/18 05:54
linux-5.15	KASAN: use-after-free Read in nr_add_node origin:upstream	19	C	error	1	35d	510d	0/3	upstream: reported C repro on 2025/01/22 09:11

Rank 🛈

linux-6.6

KASAN: slab-use-after-free Read in nr_add_node origin:upstream missing-backport

syz

error

271d

0/2

upstream: reported syz repro on 2025/09/18 05:23

linux-6.1

KASAN: use-after-free Read in nr_add_node

461d

0/3

auto-obsoleted due to no activity on 2025/06/19 16:48

linux-6.1

KASAN: use-after-free Read in nr_add_node (2) origin:upstream

error

169d

271d

0/3

upstream: reported C repro on 2025/09/18 05:54

linux-5.15

KASAN: use-after-free Read in nr_add_node origin:upstream

error

35d

510d

0/3

upstream: reported C repro on 2025/01/22 09:11

Created	Duration	User	Patch	Repo	Result
2026/06/15 03:38	27m	retest repro		upstream	OK log
2026/06/15 03:17	19m	retest repro		upstream	error
2026/06/01 01:21	17m	retest repro		upstream	error
2026/05/05 22:49	31m	retest repro		linux-next	OK log
2026/04/27 19:59	39m	retest repro		net-next	OK log
2026/04/06 02:55	14m	retest repro		upstream	report log
2026/04/06 02:55	15m	retest repro		upstream	report log
2026/03/23 00:42	16m	retest repro		upstream	report log
2026/03/08 23:21	23m	retest repro		net	report log
2026/02/22 21:35	1h37m	retest repro		linux-next	report log
2025/10/19 13:55	15m	listout@listout.xyz	patch	git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 1c64efcb083c48c85227cb4d72ab137feef2cdac	report log
2025/10/19 05:16	15m	listout@listout.xyz	patch	git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 1c64efcb083c48c85227cb4d72ab137feef2cdac	report log
2025/10/19 05:03	17m	listout@listout.xyz	patch	upstream	report log

Created

Duration

User

Patch

Repo

Result

2026/06/15 03:38

27m

retest repro

upstream

OK log

2026/06/15 03:17

19m

retest repro

upstream

error

2026/06/01 01:21

17m

retest repro

upstream

error

2026/05/05 22:49

31m

retest repro

linux-next

OK log

2026/04/27 19:59

39m

retest repro

net-next

OK log

2026/04/06 02:55

14m

retest repro

upstream

report log

2026/04/06 02:55

15m

retest repro

upstream

report log

2026/03/23 00:42

16m

retest repro

upstream

report log

2026/03/08 23:21

23m

retest repro

net

report log

2026/02/22 21:35

1h37m

retest repro

linux-next

report log

2025/10/19 13:55

15m

listout@listout.xyz

patch

git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 1c64efcb083c48c85227cb4d72ab137feef2cdac

report log

2025/10/19 05:16

15m

listout@listout.xyz

patch

git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 1c64efcb083c48c85227cb4d72ab137feef2cdac

report log

2025/10/19 05:03

17m

listout@listout.xyz

patch

upstream

report log

Created	Duration	User	Patch	Repo	Result
2026/05/13 18:39	24m	bisect fix		net	error job log
2025/12/19 23:18	3h31m	bisect fix		net	OK (0) job log log

Created

Duration

User

Patch

Repo

Result

2026/05/13 18:39

24m

bisect fix

net

error job log

2025/12/19 23:18

3h31m

bisect fix

net

OK (0) job log log

================================================================== BUG: KASAN: slab-use-after-free in nr_add_node+0x25db/0x2c00 net/netrom/nr_route.c:248 Read of size 4 at addr ffff8880296e8930 by task syz.0.2541/8740 CPU: 1 UID: 0 PID: 8740 Comm: syz.0.2541 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 nr_add_node+0x25db/0x2c00 net/netrom/nr_route.c:248 nr_rt_ioctl+0x11b7/0x29b0 net/netrom/nr_route.c:651 nr_ioctl+0x19a/0x2d0 net/netrom/af_netrom.c:1254 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5af4b8f7c9 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:00007ffea50ef728 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5af4de5fa0 RCX: 00007f5af4b8f7c9 RDX: 00002000000000c0 RSI: 000000000000890b RDI: 0000000000000004 RBP: 00007f5af4c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5af4de5fa0 R14: 00007f5af4de5fa0 R15: 0000000000000003 </TASK> Allocated by task 8735: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kmalloc_noprof include/linux/slab.h:957 [inline] nr_add_node+0xe4e/0x2c00 net/netrom/nr_route.c:146 nr_rt_ioctl+0x11b7/0x29b0 net/netrom/nr_route.c:651 nr_ioctl+0x19a/0x2d0 net/netrom/af_netrom.c:1254 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8740: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6878 nr_neigh_put include/net/netrom.h:143 [inline] nr_neigh_put include/net/netrom.h:137 [inline] nr_add_node+0x23b9/0x2c00 net/netrom/nr_route.c:246 nr_rt_ioctl+0x11b7/0x29b0 net/netrom/nr_route.c:651 nr_ioctl+0x19a/0x2d0 net/netrom/af_netrom.c:1254 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880296e8900 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 48 bytes inside of freed 64-byte region [ffff8880296e8900, ffff8880296e8940) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x296e8 ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b4428c0 ffffea0000bc2180 dead000000000003 raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 46, tgid 46 (kworker/u32:2), ts 13776761994, free_ts 13776752454 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_noprof+0x4d8/0x930 mm/slub.c:5663 kmalloc_node_noprof include/linux/slab.h:987 [inline] __vmalloc_area_node mm/vmalloc.c:3842 [inline] __vmalloc_node_range_noprof+0x405/0x16b0 mm/vmalloc.c:4051 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4111 alloc_thread_stack_node kernel/fork.c:354 [inline] dup_task_struct kernel/fork.c:923 [inline] copy_process+0x619/0x7430 kernel/fork.c:2052 kernel_clone+0xfc/0x910 kernel/fork.c:2651 user_mode_thread+0xc8/0x110 kernel/fork.c:2727 call_usermodehelper_exec_work kernel/umh.c:171 [inline] call_usermodehelper_exec_work+0xcb/0x170 kernel/umh.c:157 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 page last free pid 46 tgid 46 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline] __kasan_populate_vmalloc+0x149/0x220 mm/kasan/shadow.c:424 kasan_populate_vmalloc include/linux/kasan.h:579 [inline] alloc_vmap_area+0x98d/0x2a50 mm/vmalloc.c:2124 __get_vm_area_node+0x1ca/0x330 mm/vmalloc.c:3219 __vmalloc_node_range_noprof+0x247/0x16b0 mm/vmalloc.c:4011 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4111 alloc_thread_stack_node kernel/fork.c:354 [inline] dup_task_struct kernel/fork.c:923 [inline] copy_process+0x619/0x7430 kernel/fork.c:2052 kernel_clone+0xfc/0x910 kernel/fork.c:2651 user_mode_thread+0xc8/0x110 kernel/fork.c:2727 call_usermodehelper_exec_work kernel/umh.c:171 [inline] call_usermodehelper_exec_work+0xcb/0x170 kernel/umh.c:157 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff8880296e8800: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8880296e8880: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff8880296e8900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8880296e8980: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880296e8a00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ==================================================================

Crashes (6):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Assets (help?)	Manager	Title
2025/12/28 02:58	upstream	d26143bb38e2	d1b870e1	.config	console log	report	syz / log	C	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	KASAN: slab-use-after-free Read in nr_add_node
2025/10/18 20:36	upstream	f406055cb18c	1c8c8cd8	.config	console log	report	syz / log	C	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	KASAN: slab-use-after-free Read in nr_add_node
2025/10/22 08:32	net	2653e9c5dda5	252fbbad	.config	console log	report	syz / log	C	[disk image] [vmlinux] [kernel image]	ci-upstream-net-this-kasan-gce	KASAN: slab-use-after-free Read in nr_add_node
2025/10/19 01:08	upstream	1c64efcb083c	1c8c8cd8	.config	console log	report	syz / log	C	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-qemu-upstream	KASAN: slab-use-after-free Read in nr_add_node
2026/04/13 16:46	net-next	8806d502e0a7	9530ccf9	.config	console log	report	syz / log		[disk image] [vmlinux] [kernel image]	ci-upstream-net-kasan-gce	KASAN: slab-use-after-free Read in nr_add_node
2025/09/21 16:22	linux-next	846bd2225ec3	67c37560	.config	console log	report	syz / log		[disk image] [vmlinux] [kernel image]	ci-upstream-rust-kasan-gce	KASAN: slab-use-after-free Read in nr_add_node

Crashes (6):

Assets (help?)