syzbot


KASAN: use-after-free Write in ucma_put_ctx

Status: fixed on 2018/10/11 14:33
Subsystems: rdma
[Documentation on labels]
Reported-by: syzbot+cfe3c1e8ef634ba8964b@syzkaller.appspotmail.com
Fix commit: 5fe23f262e05 ucma: fix a use-after-free in ucma_resolve_ip()
First crash: 2054d, last: 2035d
Discussions (10)
Title Replies (including bot) Last reply
[PATCH 4.9 00/35] 4.9.133-stable review 46 (46) 2018/11/02 13:56
[PATCH 4.14 00/45] 4.14.76-stable review 54 (54) 2018/10/16 18:46
[PATCH 4.4 00/27] 4.4.161-stable review 33 (33) 2018/10/12 17:07
[PATCH 4.18 00/44] 4.18.14-stable review 49 (49) 2018/10/12 15:43
[PATCH AUTOSEL 4.18 01/58] soundwire: Fix duplicate stream state assignment 76 (76) 2018/10/12 00:03
[PATCH AUTOSEL 4.4 1/9] media: af9035: prevent buffer overflow on write 9 (9) 2018/10/08 15:27
[PATCH AUTOSEL 4.9 01/23] media: af9035: prevent buffer overflow on write 23 (23) 2018/10/08 15:27
[PATCH AUTOSEL 4.14 01/32] media: af9035: prevent buffer overflow on write 32 (32) 2018/10/08 15:26
[PATCH] ucma: fix a use-after-free in ucma_resolve_ip() 3 (3) 2018/09/13 17:05
KASAN: use-after-free Write in ucma_put_ctx 0 (1) 2018/09/07 08:01

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
hrtimer: interrupt took 24623 ns
==================================================================
BUG: KASAN: use-after-free in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:259 [inline]
BUG: KASAN: use-after-free in ucma_put_ctx+0x1d/0x60 drivers/infiniband/core/ucma.c:158
Write of size 4 at addr ffff8801d2dbb998 by task syz-executor0/6896

CPU: 0 PID: 6896 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #230
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
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 atomic_dec_and_test include/asm-generic/atomic-instrumented.h:259 [inline]
 ucma_put_ctx+0x1d/0x60 drivers/infiniband/core/ucma.c:158
 ucma_resolve_ip+0x24d/0x2a0 drivers/infiniband/core/ucma.c:713
 ucma_write+0x336/0x420 drivers/infiniband/core/ucma.c:1680
 __vfs_write+0x119/0x9f0 fs/read_write.c:485
 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
RIP: 0033:0x457099
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f792c563c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f792c5646d4 RCX: 0000000000457099
RDX: 0000000000000048 RSI: 0000000020000240 RDI: 0000000000000008
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d8100 R14: 00000000004c1c28 R15: 0000000000000001

Allocated by task 6896:
 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
 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620
 kmalloc include/linux/slab.h:513 [inline]
 kzalloc include/linux/slab.h:707 [inline]
 ucma_alloc_ctx+0xce/0x690 drivers/infiniband/core/ucma.c:205
 ucma_create_id+0x27d/0x990 drivers/infiniband/core/ucma.c:496
 ucma_write+0x336/0x420 drivers/infiniband/core/ucma.c:1680
 __vfs_write+0x119/0x9f0 fs/read_write.c:485
 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

Freed by task 6891:
 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]
 kfree+0xcf/0x230 mm/slab.c:3813
 ucma_free_ctx+0x9e6/0xdb0 drivers/infiniband/core/ucma.c:595
 ucma_close+0x10d/0x300 drivers/infiniband/core/ucma.c:1764
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d2dbb940
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 88 bytes inside of
 256-byte region [ffff8801d2dbb940, ffff8801d2dbba40)
The buggy address belongs to the page:
page:ffffea00074b6ec0 count:1 mapcount:0 mapping:ffff8801da8007c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea00074b6c48 ffffea00074b70c8 ffff8801da8007c0
raw: 0000000000000000 ffff8801d2dbb080 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2dbb880: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff8801d2dbb900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8801d2dbb980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8801d2dbba00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801d2dbba80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/10 04:03 upstream 9a5682765a2e 6b5120a4 .config console log report syz ci-upstream-kasan-gce
2018/09/07 00:22 upstream ca16eb342ebe e30d3b52 .config console log report syz ci-upstream-kasan-gce-smack-root
2018/09/06 21:48 upstream b36fdc6853a3 0bb7a7eb .config console log report syz ci-upstream-kasan-gce
2018/09/10 05:16 upstream 9a5682765a2e 6b5120a4 .config console log report syz ci-upstream-kasan-gce-386
2018/09/07 01:37 upstream ca16eb342ebe e30d3b52 .config console log report syz ci-upstream-kasan-gce-386
2018/09/26 02:18 upstream 846e8dd47c26 b7e11289 .config console log report ci-upstream-kasan-gce
2018/09/25 15:16 upstream 2dd68cc7fd8c 0e7547d7 .config console log report ci-upstream-kasan-gce-smack-root
2018/09/23 18:28 upstream 328c6333ba3d 37079712 .config console log report ci-upstream-kasan-gce-root
2018/09/22 15:29 upstream 10dc890d4228 37079712 .config console log report ci-upstream-kasan-gce
2018/09/10 03:08 upstream 9a5682765a2e 6b5120a4 .config console log report ci-upstream-kasan-gce
2018/09/08 11:26 upstream 3d0e7a9e00fd 6b5120a4 .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.