syzbot


KASAN: null-ptr-deref Write in __kernfs_remove

Status: premoderation: reported on 2024/07/29 11:23
Reported-by: syzbot+15532af093a7ed41a01a@syzkaller.appspotmail.com
First crash: 61d, last: 61d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: null-ptr-deref Write in __kernfs_remove 1 83d 83d 0/2 premoderation: reported on 2024/07/06 23:41
upstream general protection fault in __kernfs_remove kernfs 4 1030d 1130d 0/28 auto-closed as invalid on 2022/04/02 06:14
upstream KASAN: use-after-free Read in __kernfs_remove C done 3985 721d 765d 22/28 fixed on 2023/02/24 13:50

Sample crash report:
device veth0_vlan left promiscuous mode
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:86 [inline]
BUG: KASAN: null-ptr-deref in atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
BUG: KASAN: null-ptr-deref in atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
BUG: KASAN: null-ptr-deref in rwsem_clear_owner kernel/locking/rwsem.c:183 [inline]
BUG: KASAN: null-ptr-deref in __up_write kernel/locking/rwsem.c:1480 [inline]
BUG: KASAN: null-ptr-deref in up_write+0x2e/0x120 kernel/locking/rwsem.c:1621
Write of size 8 at addr 0000000000000070 by task kworker/u4:2/110

CPU: 0 PID: 110 Comm: kworker/u4:2 Tainted: G        W         5.10.222-syzkaller-01494-gfd58936f3c1f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 __kasan_report mm/kasan/report.c:439 [inline]
 kasan_report+0x167/0x1c0 mm/kasan/report.c:452
 kasan_check_range+0x293/0x2a0 mm/kasan/generic.c:189
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_write include/linux/instrumented.h:86 [inline]
 atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 rwsem_clear_owner kernel/locking/rwsem.c:183 [inline]
 __up_write kernel/locking/rwsem.c:1480 [inline]
 up_write+0x2e/0x120 kernel/locking/rwsem.c:1621
 kernfs_drain fs/kernfs/dir.c:475 [inline]
 __kernfs_remove+0x4b2/0x9d0 fs/kernfs/dir.c:1394
 kernfs_remove_by_name_ns+0xec/0x160 fs/kernfs/dir.c:1598
 kernfs_remove_by_name include/linux/kernfs.h:623 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0x10c/0x2a0 fs/sysfs/group.c:289
 sysfs_remove_groups+0x56/0xb0 fs/sysfs/group.c:313
 device_remove_groups drivers/base/core.c:2371 [inline]
 device_remove_attrs+0x113/0x130 drivers/base/core.c:2568
 device_del+0x683/0xf00 drivers/base/core.c:3451
 netdev_unregister_kobject+0x18a/0x250 net/core/net-sysfs.c:1963
 unregister_netdevice_many+0x1276/0x17d0 net/core/dev.c:10774
 default_device_exit_batch+0x38a/0x3f0 net/core/dev.c:11267
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x6e9/0xcb0 net/core/net_namespace.c:609
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
==================================================================
general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
CPU: 1 PID: 110 Comm: kworker/u4:2 Tainted: G    B   W         5.10.222-syzkaller-01494-gfd58936f3c1f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: netns cleanup_net
RIP: 0010:arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
RIP: 0010:atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
RIP: 0010:atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
RIP: 0010:rwsem_clear_owner kernel/locking/rwsem.c:183 [inline]
RIP: 0010:__up_write kernel/locking/rwsem.c:1480 [inline]
RIP: 0010:up_write+0x35/0x120 kernel/locking/rwsem.c:1621
Code: 49 89 ff 49 bc 00 00 00 00 00 fc ff df 0f 1f 44 00 00 49 8d 5f 08 48 89 df be 08 00 00 00 e8 72 d1 57 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 fc cf 57 00 49 c7 47 08 00 00 00
RSP: 0018:ffffc90000ba7610 EFLAGS: 00010202
RAX: 000000000000000e RBX: 0000000000000070 RCX: ffff88810d5013c0
RDX: 0000000000000000 RSI: 0000000000000282 RDI: 00000000ffffffff
RBP: ffffc90000ba7630 R08: ffffffff813e275b R09: 0000000000000003
R10: fffffbfff0e10c48 R11: dffffc0000000001 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888107fed004 R15: 0000000000000068
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd4c9806ab8 CR3: 000000010c879000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kernfs_drain fs/kernfs/dir.c:475 [inline]
 __kernfs_remove+0x4b2/0x9d0 fs/kernfs/dir.c:1394
 kernfs_remove_by_name_ns+0xec/0x160 fs/kernfs/dir.c:1598
 kernfs_remove_by_name include/linux/kernfs.h:623 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0x10c/0x2a0 fs/sysfs/group.c:289
 sysfs_remove_groups+0x56/0xb0 fs/sysfs/group.c:313
 device_remove_groups drivers/base/core.c:2371 [inline]
 device_remove_attrs+0x113/0x130 drivers/base/core.c:2568
 device_del+0x683/0xf00 drivers/base/core.c:3451
 netdev_unregister_kobject+0x18a/0x250 net/core/net-sysfs.c:1963
 unregister_netdevice_many+0x1276/0x17d0 net/core/dev.c:10774
 default_device_exit_batch+0x38a/0x3f0 net/core/dev.c:11267
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x6e9/0xcb0 net/core/net_namespace.c:609
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Modules linked in:
---[ end trace 886394d48d77c520 ]---
RIP: 0010:arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
RIP: 0010:atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
RIP: 0010:atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
RIP: 0010:rwsem_clear_owner kernel/locking/rwsem.c:183 [inline]
RIP: 0010:__up_write kernel/locking/rwsem.c:1480 [inline]
RIP: 0010:up_write+0x35/0x120 kernel/locking/rwsem.c:1621
Code: 49 89 ff 49 bc 00 00 00 00 00 fc ff df 0f 1f 44 00 00 49 8d 5f 08 48 89 df be 08 00 00 00 e8 72 d1 57 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 fc cf 57 00 49 c7 47 08 00 00 00
RSP: 0018:ffffc90000ba7610 EFLAGS: 00010202
RAX: 000000000000000e RBX: 0000000000000070 RCX: ffff88810d5013c0
RDX: 0000000000000000 RSI: 0000000000000282 RDI: 00000000ffffffff
RBP: ffffc90000ba7630 R08: ffffffff813e275b R09: 0000000000000003
R10: fffffbfff0e10c48 R11: dffffc0000000001 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888107fed004 R15: 0000000000000068
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efe1a0e9000 CR3: 000000011d3c1000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	49 89 ff             	mov    %rdi,%r15
   3:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
   a:	fc ff df
   d:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  12:	49 8d 5f 08          	lea    0x8(%r15),%rbx
  16:	48 89 df             	mov    %rbx,%rdi
  19:	be 08 00 00 00       	mov    $0x8,%esi
  1e:	e8 72 d1 57 00       	call   0x57d195
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 fc cf 57 00       	call   0x57d035
  39:	49                   	rex.WB
  3a:	c7                   	.byte 0xc7
  3b:	47 08 00             	rex.RXB or %r8b,(%r8)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/29 11:22 android13-5.10-lts fd58936f3c1f 5187fc86 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Write in __kernfs_remove
* Struck through repros no longer work on HEAD.