syzbot


KASAN: use-after-free Read in fuse_dev_do_read

Status: fixed on 2018/11/12 21:25
Subsystems: fuse
[Documentation on labels]
Reported-by: syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com
Fix commit: bc78abbd55dd fuse: Fix use-after-free in fuse_dev_do_read()
First crash: 2077d, last: 2029d
Discussions (8)
Title Replies (including bot) Last reply
[PATCH 4.19 000/205] 4.19.3-stable review 214 (214) 2018/11/21 08:05
[PATCH 4.4 000/160] 4.4.164-stable review 169 (169) 2018/11/21 07:59
[PATCH 4.18 000/171] 4.18.20-stable review 176 (176) 2018/11/20 20:40
[PATCH 4.14 000/124] 4.14.82-stable review 131 (131) 2018/11/20 20:39
[PATCH 4.9 00/83] 4.9.138-stable review 89 (89) 2018/11/20 20:39
[PATCH] fuse: Fix use-after-free in fuse_dev_do_write() 2 (2) 2018/10/01 09:26
[PATCH] fuse: Fix use-after-free in fuse_dev_do_read() 2 (2) 2018/10/01 09:25
KASAN: use-after-free Read in fuse_dev_do_read 4 (6) 2018/09/24 14:27
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 KASAN: use-after-free Read in fuse_dev_do_read C 9 2048d 1864d 0/3 public: reported C repro on 2019/04/14 00:00

Sample crash report:
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
==================================================================
BUG: KASAN: use-after-free in constant_test_bit arch/x86/include/asm/bitops.h:328 [inline]
BUG: KASAN: use-after-free in fuse_dev_do_read.isra.27+0x1659/0x1920 fs/fuse/dev.c:1318
Read of size 8 at addr ffff8801d32e8a30 by task syz-executor2/8682

CPU: 0 PID: 8682 Comm: syz-executor2 Not tainted 4.19.0-rc6+ #262
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 constant_test_bit arch/x86/include/asm/bitops.h:328 [inline]
 fuse_dev_do_read.isra.27+0x1659/0x1920 fs/fuse/dev.c:1318
 fuse_dev_read+0x1a9/0x250 fs/fuse/dev.c:1360
 call_read_iter include/linux/fs.h:1802 [inline]
 new_sync_read fs/read_write.c:406 [inline]
 __vfs_read+0x6ac/0x9b0 fs/read_write.c:418
 vfs_read+0x17f/0x3c0 fs/read_write.c:452
 ksys_read+0x101/0x260 fs/read_write.c:578
 __do_sys_read fs/read_write.c:588 [inline]
 __se_sys_read fs/read_write.c:586 [inline]
 __x64_sys_read+0x73/0xb0 fs/read_write.c:586
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f9e2ebf7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000000001000 RSI: 00000000200030c0 RDI: 0000000000000006
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9e2ebf86d4
R13: 00000000004c31b7 R14: 00000000004d4c98 R15: 00000000ffffffff

Allocated by task 8682:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 __fuse_request_alloc+0x27/0xf0 fs/fuse/dev.c:58
 fuse_request_alloc+0x18/0x20 fs/fuse/dev.c:89
 fuse_fill_super+0x12bf/0x1ea0 fs/fuse/inode.c:1157
 mount_nodev+0x6b/0x110 fs/super.c:1204
 fuse_mount+0x2c/0x40 fs/fuse/inode.c:1213
 mount_fs+0xae/0x31d fs/super.c:1261
 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2457 [inline]
 do_mount+0x581/0x31f0 fs/namespace.c:2787
 ksys_mount+0x12d/0x140 fs/namespace.c:3003
 __do_sys_mount fs/namespace.c:3017 [inline]
 __se_sys_mount fs/namespace.c:3014 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8723:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3756
 fuse_request_free+0x8b/0xa0 fs/fuse/dev.c:104
 fuse_put_request+0x2a6/0x350 fs/fuse/dev.c:304
 request_end+0xba/0xaa0 fs/fuse/dev.c:414
 fuse_dev_do_write+0x192e/0x36e0 fs/fuse/dev.c:1915
 fuse_dev_write+0x19a/0x240 fs/fuse/dev.c:1939
 call_write_iter include/linux/fs.h:1808 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6b8/0x9f0 fs/read_write.c:487
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d32e8a00
 which belongs to the cache fuse_request of size 448
The buggy address is located 48 bytes inside of
 448-byte region [ffff8801d32e8a00, ffff8801d32e8bc0)
The buggy address belongs to the page:
page:ffffea00074cba00 count:1 mapcount:0 mapping:ffff8801d4a7d840 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006e5c948 ffffea0006e5ca08 ffff8801d4a7d840
raw: 0000000000000000 ffff8801d32e8000 0000000100000008 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d32e8900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d32e8980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8801d32e8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8801d32e8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d32e8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/10/01 01:37 upstream 17b57b1883c1 41e4b329 .config console log report syz ci-upstream-kasan-gce-root
2018/10/01 01:33 upstream 17b57b1883c1 41e4b329 .config console log report syz ci-upstream-kasan-gce-selinux-root
2018/09/22 19:29 upstream 10dc890d4228 37079712 .config console log report syz ci-upstream-kasan-gce-smack-root
2018/10/31 05:11 upstream 310c7585e830 4ccf7bb4 .config console log report ci-upstream-kasan-gce
2018/10/30 20:18 upstream 11743c56785c 8dbb755a .config console log report ci-upstream-kasan-gce-selinux-root
2018/10/29 13:13 upstream 9f51ae62c84a 7df9db2e .config console log report ci-upstream-kasan-gce-smack-root
2018/10/26 19:52 upstream 18d0eae30e6a a8292de9 .config console log report ci-upstream-kasan-gce
2018/10/26 09:32 upstream e5f6d9afa341 a8292de9 .config console log report ci-upstream-kasan-gce-smack-root
2018/10/25 21:40 upstream bd6bf7c10484 a8292de9 .config console log report ci-upstream-kasan-gce-selinux-root
2018/10/22 15:11 upstream 84df9525b0c2 ecb386fe .config console log report ci-upstream-kasan-gce
2018/10/15 06:56 upstream 35a7f35ad1b1 caf12900 .config console log report ci-upstream-kasan-gce
2018/10/07 08:19 upstream c1d84a1b42ef 8b311eaf .config console log report ci-upstream-kasan-gce-root
2018/09/30 09:56 upstream 291d0e5d81e1 41e4b329 .config console log report ci-upstream-kasan-gce-root
2018/09/29 12:11 upstream e704966c45e4 41e4b329 .config console log report ci-upstream-kasan-gce
2018/09/22 18:52 upstream 10dc890d4228 37079712 .config console log report ci-upstream-kasan-gce-smack-root
2018/09/14 12:27 upstream a06b0c82a049 a343a400 .config console log report ci-upstream-kasan-gce-root
2018/09/13 08:43 upstream 54eda9df17f3 71907daf .config console log report ci-upstream-kasan-gce-selinux-root
2018/09/13 06:35 upstream 54eda9df17f3 71907daf .config console log report ci-upstream-kasan-gce-smack-root
2018/09/24 06:23 linux-next dad486875956 28d9ac76 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.