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

Status: upstream: reported syz repro on 2026/04/09 06:50
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+324fb5bceaebab33cb61@syzkaller.appspotmail.com
First crash: 118d, last: 116d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/04/11 linux-6.6.y (ToT) 80de0a958133 syz [report] KASAN: slab-use-after-free Read in __pm_runtime_resume
2026/04/11 upstream (ToT) e774d5f1bc27 syz Didn't crash
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: null-ptr-deref Write in __pm_runtime_resume pm 12 syz, C done 108 1625d 1803d 20/29 fixed on 2022/03/08 16:11
linux-6.1 KASAN: use-after-free Read in __pm_runtime_resume origin:lts-only 19 syz, C error 12 116d 120d 0/3 upstream: reported C repro on 2026/04/07 03:09
upstream general protection fault in __pm_runtime_resume (2) pm 2 syz, C error 7 1597d 1606d 22/29 fixed on 2023/02/24 13:50
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2026/05/14 09:33 12m fix candidate upstream error job log
2026/04/11 19:14 1m fix candidate upstream error job log

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in __pm_runtime_resume+0x14c/0x170 drivers/base/power/runtime.c:1163
Read of size 2 at addr ffff8880602f09a8 by task syz.2.19/6077

CPU: 0 PID: 6077 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 __pm_runtime_resume+0x14c/0x170 drivers/base/power/runtime.c:1163
 pm_runtime_get_sync include/linux/pm_runtime.h:421 [inline]
 ethnl_ops_begin+0x5d/0x1f0 net/ethtool/netlink.c:41
 module_prepare_data+0x46/0x100 net/ethtool/module.c:47
 ethnl_default_doit+0x4fa/0xb80 net/ethtool/netlink.c:402
 genl_family_rcv_msg_doit+0x211/0x310 net/netlink/genetlink.c:971
 genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
 genl_rcv_msg+0x619/0x7a0 net/netlink/genetlink.c:1066
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe93f39c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe93e9dd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe93f616090 RCX: 00007fe93f39c819
RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000000000000004
RBP: 00007fe93f432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe93f616128 R14: 00007fe93f616090 R15: 00007ffe84ffc5a8
 </TASK>

Allocated by task 5894:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node+0xb4/0x230 mm/slab_common.c:1014
 kmalloc_node include/linux/slab.h:620 [inline]
 kvmalloc_node+0x70/0x180 mm/util.c:617
 kvmalloc include/linux/slab.h:738 [inline]
 kvzalloc include/linux/slab.h:746 [inline]
 alloc_netdev_mqs+0x87/0x1040 net/core/dev.c:10855
 rtnl_create_link+0x30e/0xd00 net/core/rtnetlink.c:3384
 veth_newlink+0x2bc/0xc30 drivers/net/veth.c:1860
 rtnl_newlink_create net/core/rtnetlink.c:3520 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3740 [inline]
 rtnl_newlink+0x1542/0x20a0 net/core/rtnetlink.c:3753
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6475
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x4a9/0x6b0 net/socket.c:2200
 __do_sys_sendto net/socket.c:2212 [inline]
 __se_sys_sendto net/socket.c:2208 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2208
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 6065:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843
 device_release+0x96/0x1c0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x221/0x460 lib/kobject.c:737
 netdev_run_todo+0xcb7/0xdc0 net/core/dev.c:10627
 rtnl_unlock net/core/rtnetlink.c:151 [inline]
 rtnetlink_rcv_msg+0xab7/0xfa0 net/core/rtnetlink.c:6476
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff8880602f0000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 2472 bytes inside of
 freed 4096-byte region [ffff8880602f0000, ffff8880602f1000)

The buggy address belongs to the physical page:
page:ffffea000180bc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x602f0
head:ffffea000180bc00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88807606c5c1
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c4f500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88807606c5c1
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5894, tgid 5894 (syz-executor), ts 126060018502, free_ts 119788161534
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
 prep_new_page mm/page_alloc.c:1588 [inline]
 get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500
 alloc_slab_page+0x5d/0x160 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node+0xa4/0x230 mm/slab_common.c:1014
 kmalloc_node include/linux/slab.h:620 [inline]
 kvmalloc_node+0x70/0x180 mm/util.c:617
 kvmalloc include/linux/slab.h:738 [inline]
 kvzalloc include/linux/slab.h:746 [inline]
 alloc_netdev_mqs+0x87/0x1040 net/core/dev.c:10855
 rtnl_create_link+0x30e/0xd00 net/core/rtnetlink.c:3384
 veth_newlink+0x2bc/0xc30 drivers/net/veth.c:1860
 rtnl_newlink_create net/core/rtnetlink.c:3520 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3740 [inline]
 rtnl_newlink+0x1542/0x20a0 net/core/rtnetlink.c:3753
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6475
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1181 [inline]
 free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
 vfree+0x1a6/0x320 mm/vmalloc.c:2868
 kcov_put kernel/kcov.c:438 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:534
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x95a/0x2460 kernel/exit.c:883
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x13f0 kernel/signal.c:2902
 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff8880602f0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880602f0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880602f0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff8880602f0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880602f0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/11 05:24 linux-6.6.y 80de0a958133 38c8e246 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in __pm_runtime_resume
2026/04/09 23:53 linux-6.6.y 80de0a958133 38c8e246 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in __pm_runtime_resume
2026/04/09 20:59 linux-6.6.y 80de0a958133 38c8e246 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in __pm_runtime_resume
2026/04/09 06:49 linux-6.6.y 80de0a958133 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in __pm_runtime_resume
* Struck through repros no longer work on HEAD.