syzbot

 sign-in | mailing list | source | docs
🐞 Open [1523]
≡ Subsystems
🐞 Fixed [6469]
🐞 Invalid [16404]
⬇ Missing Backports [198]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

KASAN: use-after-free Read in handle_userfault (3)

Status: closed as invalid on 2019/02/12 06:42
Subsystems: fs mm
[Documentation on labels]
First crash: 2360d, last: 2360d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in handle_userfault (4) mm fs 19 14 1140d 1171d 0/29 auto-closed as invalid on 2022/08/15 08:51
upstream KASAN: use-after-free Read in handle_userfault (2) fs mm 19 1 2422d 2422d 0/29 closed as dup on 2019/01/07 09:45
upstream KASAN: use-after-free Read in handle_userfault fs mm 19 C 151 2770d 2833d 3/29 fixed on 2018/01/10 09:03

Sample crash report:
=continue" or missing value
gfs2: not a GFS2 filesystem
FAULT_FLAG_ALLOW_RETRY missing 70
==================================================================
CPU: 1 PID: 2163 Comm: syz-executor.1 Not tainted 5.0.0-rc6 #67
BUG: KASAN: use-after-free in __list_del_entry_valid+0xe6/0xf5 lib/list_debug.c:51
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Read of size 8 at addr ffff888094bf06a0 by task syz-executor.4/2161
Call Trace:

 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 handle_userfault.cold+0x41/0x5d fs/userfaultfd.c:431
 do_anonymous_page mm/memory.c:2921 [inline]
 handle_pte_fault mm/memory.c:3785 [inline]
 __handle_mm_fault+0x36c8/0x3f20 mm/memory.c:3911
 handle_mm_fault+0x43f/0xb30 mm/memory.c:3948
 do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
 __do_page_fault+0x5da/0xd60 arch/x86/mm/fault.c:1541
 do_page_fault+0x71/0x581 arch/x86/mm/fault.c:1572
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
RIP: 0033:0x451880
Code: 0f 84 c4 0f 00 00 48 89 f1 48 89 f8 48 83 e1 3f 48 83 f9 20 0f 86 7b 02 00 00 48 83 e6 f0 48 83 e1 0f 66 0f ef c0 66 0f ef c9 <66> 0f 74 0e 66 0f d7 d1 48 d3 ea 49 c7 c2 11 00 00 00 49 29 ca 4d
RSP: 002b:00007f04692d67a8 EFLAGS: 00010202
RAX: 00007f04692d6850 RBX: 0000000000000003 RCX: 000000000000000e
RDX: 00000000000003ff RSI: 0000000020012fe0 RDI: 00007f04692d6850
RBP: 000000000073bf00 R08: 00000000000003ff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f04692d76d4
R13: 00000000004c68be R14: 00000000004dbdb8 R15: 00000000ffffffff
CPU: 0 PID: 2161 Comm: syz-executor.4 Not tainted 5.0.0-rc6 #67
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 __list_del_entry_valid+0xe6/0xf5 lib/list_debug.c:51
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 cma_cancel_listens drivers/infiniband/core/cma.c:1722 [inline]
 cma_cancel_operation drivers/infiniband/core/cma.c:1750 [inline]
 cma_cancel_operation+0x2d7/0xa10 drivers/infiniband/core/cma.c:1738
 rdma_destroy_id+0x8d/0xab0 drivers/infiniband/core/cma.c:1814
 ucma_close+0x115/0x320 drivers/infiniband/core/ucma.c:1770
 __fput+0x2df/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x411d41
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 94 19 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffe1b30ea30 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000411d41
RDX: 0000000000000000 RSI: 0000000000743940 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000743938 R09: 00000000001a57ae
R10: 00007ffe1b30e950 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 00000000000008ed R15: 0000000000000004

Allocated by task 2162:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 kzalloc include/linux/slab.h:740 [inline]
 __rdma_create_id+0x5f/0x4e0 drivers/infiniband/core/cma.c:879
 ucma_create_id+0x1de/0x640 drivers/infiniband/core/ucma.c:506
 ucma_write+0x2da/0x3c0 drivers/infiniband/core/ucma.c:1689
 __vfs_write+0x116/0x8e0 fs/read_write.c:485
 vfs_write+0x20c/0x580 fs/read_write.c:549
 ksys_write+0xea/0x1f0 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+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 2161:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 rdma_destroy_id+0x723/0xab0 drivers/infiniband/core/cma.c:1849
 ucma_close+0x115/0x320 drivers/infiniband/core/ucma.c:1770
 __fput+0x2df/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888094bf04c0
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 480 bytes inside of
 2048-byte region [ffff888094bf04c0, ffff888094bf0cc0)
The buggy address belongs to the page:
page:ffffea000252fc00 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000171e688 ffffea0001682308 ffff88812c3f0c40
raw: 0000000000000000 ffff888094bf04c0 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888094bf0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888094bf0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888094bf0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888094bf0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888094bf0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/02/11 22:17 upstream d13937116f1e 73f5f452 .config console log report ci-upstream-kasan-gce-selinux-root
* Struck through repros no longer work on HEAD.