KASAN: use-after-free Read in rdma_listen

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e109a984 Linux 4.19.48
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12e20986a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=2d14dd88554f26bc
dashboard link: https://syzkaller.appspot.com/bug?extid=f7c4563f141eafeca5b5
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11a5cefea00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f7c456...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
audit: type=1400 audit(1559763566.737:38): avc: denied { associate } for
pid=7899 comm="syz-executor.0" name="syz0"
scontext=unconfined_u:object_r:unlabeled_t:s0
tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1
==================================================================
BUG: KASAN: use-after-free in __list_add_valid+0x9a/0xa0 lib/list_debug.c:26
Read of size 8 at addr ffff888094f2eea0 by task syz-executor.0/7912

CPU: 0 PID: 7912 Comm: syz-executor.0 Not tainted 4.19.48 #20
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:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
__list_add_valid+0x9a/0xa0 lib/list_debug.c:26
__list_add include/linux/list.h:60 [inline]
list_add_tail include/linux/list.h:93 [inline]
cma_listen_on_all drivers/infiniband/core/cma.c:2379 [inline]
rdma_listen+0x63b/0x8e0 drivers/infiniband/core/cma.c:3407
ucma_listen+0x14d/0x1c0 drivers/infiniband/core/ucma.c:1100
ucma_write+0x2d7/0x3c0 drivers/infiniband/core/ucma.c:1689
__vfs_write+0x114/0x810 fs/read_write.c:485
vfs_write+0x20c/0x560 fs/read_write.c:549
ksys_write+0x14f/0x2d0 fs/read_write.c:599
__do_sys_write fs/read_write.c:611 [inline]
__se_sys_write fs/read_write.c:608 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:608
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459279
Code: fd b7 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 b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f330f4dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459279
RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f330f4db6d4
R13: 00000000004c8ca5 R14: 00000000004df850 R15: 00000000ffffffff

Allocated by task 7906:
save_stack+0x45/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
kmem_cache_alloc_trace+0x152/0x760 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
__rdma_create_id+0x5e/0x610 drivers/infiniband/core/cma.c:784
ucma_create_id+0x1de/0x640 drivers/infiniband/core/ucma.c:506
ucma_write+0x2d7/0x3c0 drivers/infiniband/core/ucma.c:1689
__vfs_write+0x114/0x810 fs/read_write.c:485
vfs_write+0x20c/0x560 fs/read_write.c:549
ksys_write+0x14f/0x2d0 fs/read_write.c:599
__do_sys_write fs/read_write.c:611 [inline]
__se_sys_write fs/read_write.c:608 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:608
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7905:
save_stack+0x45/0xd0 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:3503 [inline]
kfree+0xcf/0x220 mm/slab.c:3822
rdma_destroy_id+0x729/0xab0 drivers/infiniband/core/cma.c:1752
ucma_close+0x115/0x320 drivers/infiniband/core/ucma.c:1770
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:193 [inline]
exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888094f2ecc0
which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 480 bytes inside of
2048-byte region [ffff888094f2ecc0, ffff888094f2f4c0)
The buggy address belongs to the page:
page:ffffea000253cb80 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0
compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffffea0002509e88 ffffea000255a988 ffff88812c3f0c40
raw: 0000000000000000 ffff888094f2e440 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888094f2ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888094f2ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888094f2ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888094f2ef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888094f2ef80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot can test patches for this bug, for details see:
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[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e6a95d88 Linux 4.14.124
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14aa7dd2a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ab7251aa14ac721d
dashboard link: https://syzkaller.appspot.com/bug?extid=e57ae567bab1748839c5

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17d13cb6a00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f33996a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:

Reported-by: syzbot+e57ae5...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __list_add_valid+0x9a/0xa0 lib/list_debug.c:26

Read of size 8 at addr ffff888074b8e658 by task syz-executor088/7101

CPU: 0 PID: 7101 Comm: syz-executor088 Not tainted 4.14.124 #18

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:

__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report mm/kasan/report.c:409 [inline]
kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430

__list_add_valid+0x9a/0xa0 lib/list_debug.c:26
__list_add include/linux/list.h:60 [inline]
list_add_tail include/linux/list.h:93 [inline]

cma_listen_on_all drivers/infiniband/core/cma.c:2320 [inline]
rdma_listen+0x5a7/0x840 drivers/infiniband/core/cma.c:3318
ucma_listen+0x10e/0x170 drivers/infiniband/core/ucma.c:1078
ucma_write+0x231/0x310 drivers/infiniband/core/ucma.c:1672
__vfs_write+0x105/0x6b0 fs/read_write.c:480
vfs_write+0x198/0x500 fs/read_write.c:544
SYSC_write fs/read_write.c:589 [inline]
SyS_write+0xb8/0x180 fs/read_write.c:581
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x441379
RSP: 002b:00007ffd12a95c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441379
RDX: 0000000000000010 RSI: 00000000200002c0 RDI: 0000000000000003
RBP: 0000000000011c1f R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 00000000004021a0
R13: 0000000000402230 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 7039:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc mm/kasan/kasan.c:551 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
kmalloc include/linux/slab.h:488 [inline]
kzalloc include/linux/slab.h:661 [inline]
rdma_create_id+0x5a/0x4d0 drivers/infiniband/core/cma.c:790
ucma_create_id+0x19b/0x5b0 drivers/infiniband/core/ucma.c:484
ucma_write+0x231/0x310 drivers/infiniband/core/ucma.c:1672
__vfs_write+0x105/0x6b0 fs/read_write.c:480
vfs_write+0x198/0x500 fs/read_write.c:544
SYSC_write fs/read_write.c:589 [inline]
SyS_write+0xb8/0x180 fs/read_write.c:581
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 7039:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x45/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xcc/0x270 mm/slab.c:3815
rdma_destroy_id+0x6fb/0xb70 drivers/infiniband/core/cma.c:1725
ucma_close+0x110/0x310 drivers/infiniband/core/ucma.c:1753
__fput+0x275/0x7a0 fs/file_table.c:210
____fput+0x16/0x20 fs/file_table.c:244
task_work_run+0x114/0x190 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x7df/0x2c10 kernel/exit.c:874
do_group_exit+0x111/0x330 kernel/exit.c:977
SYSC_exit_group kernel/exit.c:988 [inline]
SyS_exit_group+0x1d/0x20 kernel/exit.c:986
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff888074b8e480
which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 472 bytes inside of
1024-byte region [ffff888074b8e480, ffff888074b8e880)

The buggy address belongs to the page:

page:ffffea0001d2e380 count:1 mapcount:0 mapping:ffff888074b8e000 index:0x0

compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)

raw: 01fffc0000008100 ffff888074b8e000 0000000000000000 0000000100000007
raw: ffffea0001d2e320 ffffea0001e8e4a0 ffff8880aa800ac0 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff888074b8e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888074b8e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888074b8e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888074b8e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888074b8e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

[syzbot]

syzbot suspects this bug was fixed by commit:

commit abc4ea7f1345398261295345fd9b30243e4f4f8e
Author: Jason Gunthorpe <j...@mellanox.com>
Date: Tue Feb 18 19:45:38 2020 +0000

RDMA/ucma: Put a lock around every call to the rdma_cm layer

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12b32cb2100000
start commit: dda0e292 Linux 4.19.114
git tree: linux-4.19.y
kernel config: https://syzkaller.appspot.com/x/.config?x=f32ac7e5b2d5c341
dashboard link: https://syzkaller.appspot.com/bug?extid=f7c4563f141eafeca5b5
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1756abb3e00000

If the result looks correct, please mark the bug fixed by replying with:

#syz fix: RDMA/ucma: Put a lock around every call to the rdma_cm layer

For information about bisection process see: https://goo.gl/tpsmEJ#bisection