[syzbot] KASAN: use-after-free Write in dec_rlimit_ucounts
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syzbot
Jul 17, 2021, 2:22:20 AM7/17/21
to ebie...@xmission.com, leg...@kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 3dbdb38e2869 Merge branch 'for-5.14' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11f4b9d8300000
kernel config: https://syzkaller.appspot.com/x/.config?x=1700b0b2b41cd52c
dashboard link: https://syzkaller.appspot.com/bug?extid=01985d7909f9468f013c
compiler: Debian clang version 11.0.1-2
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01985d...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
BUG: KASAN: use-after-free in atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
BUG: KASAN: use-after-free in dec_rlimit_ucounts+0x88/0x170 kernel/ucount.c:272
Write of size 8 at addr ffff888021498d80 by task syz-executor.1/32612
CPU: 0 PID: 32612 Comm: syz-executor.1 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:96
print_address_description+0x66/0x3b0 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report+0x163/0x210 mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:135 [inline]
kasan_check_range+0x2b5/0x2f0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
dec_rlimit_ucounts+0x88/0x170 kernel/ucount.c:272
release_task+0x323/0x15a0 kernel/exit.c:191
exit_notify kernel/exit.c:699 [inline]
do_exit+0x1aa2/0x2510 kernel/exit.c:845
do_group_exit+0x168/0x2d0 kernel/exit.c:922
get_signal+0x16c0/0x20d0 kernel/signal.c:2796
arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:789
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:209
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302
do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: Unable to access opcode bytes at RIP 0x4665af.
RSP: 002b:00007fa6e68ec218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 000000000056bf88 RCX: 00000000004665d9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000056bf8c
RBP: 000000000056bf80 R08: 000000000000000d R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000056bf8c
R13: 00007fff105041ff R14: 00007fa6e68ec300 R15: 0000000000022000
Allocated by task 32600:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc+0xc4/0xf0 mm/kasan/common.c:513
kasan_kmalloc include/linux/kasan.h:263 [inline]
kmem_cache_alloc_trace+0x96/0x340 mm/slub.c:2997
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
alloc_ucounts+0x176/0x420 kernel/ucount.c:169
set_cred_ucounts+0x220/0x2d0 kernel/cred.c:684
__sys_setuid+0x355/0x4a0 kernel/sys.c:623
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 32580:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x3d/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0x109/0x150 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:229 [inline]
slab_free_hook mm/slub.c:1639 [inline]
slab_free_freelist_hook+0x1d8/0x290 mm/slub.c:1664
slab_free mm/slub.c:3224 [inline]
kfree+0xcf/0x2d0 mm/slub.c:4268
put_cred_rcu+0x221/0x400 kernel/cred.c:124
rcu_do_batch kernel/rcu/tree.c:2558 [inline]
rcu_core+0x906/0x14b0 kernel/rcu/tree.c:2793
__do_softirq+0x372/0x783 kernel/softirq.c:558
The buggy address belongs to the object at ffff888021498d00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
192-byte region [ffff888021498d00, ffff888021498dc0)
The buggy address belongs to the page:
page:ffffea0000852600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21498
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0001c8ac80 0000000400000004 ffff888011841a00
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 32273, ts 862400369934, free_ts 857108006622
prep_new_page mm/page_alloc.c:2445 [inline]
get_page_from_freelist+0x779/0xa30 mm/page_alloc.c:4178
__alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5386
alloc_slab_page mm/slub.c:1702 [inline]
allocate_slab+0xf1/0x540 mm/slub.c:1842
new_slab mm/slub.c:1905 [inline]
new_slab_objects mm/slub.c:2651 [inline]
___slab_alloc+0x1cf/0x350 mm/slub.c:2814
__slab_alloc mm/slub.c:2854 [inline]
slab_alloc_node mm/slub.c:2936 [inline]
slab_alloc mm/slub.c:2978 [inline]
kmem_cache_alloc_trace+0x29d/0x340 mm/slub.c:2995
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
push_stack+0x86/0x710 kernel/bpf/verifier.c:1019
check_cond_jmp_op kernel/bpf/verifier.c:8815 [inline]
do_check+0x18d54/0x218b0 kernel/bpf/verifier.c:10882
do_check_common+0xc01/0x21a0 kernel/bpf/verifier.c:12865
do_check_main kernel/bpf/verifier.c:12931 [inline]
bpf_check+0x112e2/0x14720 kernel/bpf/verifier.c:13498
bpf_prog_load kernel/bpf/syscall.c:2274 [inline]
__sys_bpf+0x10923/0x11d80 kernel/bpf/syscall.c:4469
__do_sys_bpf kernel/bpf/syscall.c:4573 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4571 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4571
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1355 [inline]
free_pcp_prepare+0xc29/0xd20 mm/page_alloc.c:1406
free_unref_page_prepare mm/page_alloc.c:3341 [inline]
free_unref_page_list+0x118/0xad0 mm/page_alloc.c:3457
release_pages+0x18bb/0x1af0 mm/swap.c:972
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
tlb_flush_mmu+0x780/0x910 mm/mmu_gather.c:249
tlb_finish_mmu+0xcb/0x200 mm/mmu_gather.c:340
exit_mmap+0x404/0x7a0 mm/mmap.c:3204
__mmput+0x111/0x370 kernel/fork.c:1101
exit_mm+0x60a/0x770 kernel/exit.c:501
do_exit+0x6ae/0x2510 kernel/exit.c:812
do_group_exit+0x168/0x2d0 kernel/exit.c:922
__do_sys_exit_group+0x13/0x20 kernel/exit.c:933
__ia32_sys_exit_group+0x0/0x40 kernel/exit.c:931
__x64_sys_exit_group+0x37/0x40 kernel/exit.c:931
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Memory state around the buggy address:
ffff888021498c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888021498d00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888021498d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888021498e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888021498e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot found the following issue on:
HEAD commit: 3dbdb38e2869 Merge branch 'for-5.14' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11f4b9d8300000
kernel config: https://syzkaller.appspot.com/x/.config?x=1700b0b2b41cd52c
dashboard link: https://syzkaller.appspot.com/bug?extid=01985d7909f9468f013c
compiler: Debian clang version 11.0.1-2
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01985d...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
BUG: KASAN: use-after-free in atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
BUG: KASAN: use-after-free in dec_rlimit_ucounts+0x88/0x170 kernel/ucount.c:272
Write of size 8 at addr ffff888021498d80 by task syz-executor.1/32612
CPU: 0 PID: 32612 Comm: syz-executor.1 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:96
print_address_description+0x66/0x3b0 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report+0x163/0x210 mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:135 [inline]
kasan_check_range+0x2b5/0x2f0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
dec_rlimit_ucounts+0x88/0x170 kernel/ucount.c:272
release_task+0x323/0x15a0 kernel/exit.c:191
exit_notify kernel/exit.c:699 [inline]
do_exit+0x1aa2/0x2510 kernel/exit.c:845
do_group_exit+0x168/0x2d0 kernel/exit.c:922
get_signal+0x16c0/0x20d0 kernel/signal.c:2796
arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:789
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:209
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302
do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: Unable to access opcode bytes at RIP 0x4665af.
RSP: 002b:00007fa6e68ec218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 000000000056bf88 RCX: 00000000004665d9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000056bf8c
RBP: 000000000056bf80 R08: 000000000000000d R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000056bf8c
R13: 00007fff105041ff R14: 00007fa6e68ec300 R15: 0000000000022000
Allocated by task 32600:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc+0xc4/0xf0 mm/kasan/common.c:513
kasan_kmalloc include/linux/kasan.h:263 [inline]
kmem_cache_alloc_trace+0x96/0x340 mm/slub.c:2997
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
alloc_ucounts+0x176/0x420 kernel/ucount.c:169
set_cred_ucounts+0x220/0x2d0 kernel/cred.c:684
__sys_setuid+0x355/0x4a0 kernel/sys.c:623
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 32580:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x3d/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0x109/0x150 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:229 [inline]
slab_free_hook mm/slub.c:1639 [inline]
slab_free_freelist_hook+0x1d8/0x290 mm/slub.c:1664
slab_free mm/slub.c:3224 [inline]
kfree+0xcf/0x2d0 mm/slub.c:4268
put_cred_rcu+0x221/0x400 kernel/cred.c:124
rcu_do_batch kernel/rcu/tree.c:2558 [inline]
rcu_core+0x906/0x14b0 kernel/rcu/tree.c:2793
__do_softirq+0x372/0x783 kernel/softirq.c:558
The buggy address belongs to the object at ffff888021498d00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
192-byte region [ffff888021498d00, ffff888021498dc0)
The buggy address belongs to the page:
page:ffffea0000852600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21498
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0001c8ac80 0000000400000004 ffff888011841a00
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 32273, ts 862400369934, free_ts 857108006622
prep_new_page mm/page_alloc.c:2445 [inline]
get_page_from_freelist+0x779/0xa30 mm/page_alloc.c:4178
__alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5386
alloc_slab_page mm/slub.c:1702 [inline]
allocate_slab+0xf1/0x540 mm/slub.c:1842
new_slab mm/slub.c:1905 [inline]
new_slab_objects mm/slub.c:2651 [inline]
___slab_alloc+0x1cf/0x350 mm/slub.c:2814
__slab_alloc mm/slub.c:2854 [inline]
slab_alloc_node mm/slub.c:2936 [inline]
slab_alloc mm/slub.c:2978 [inline]
kmem_cache_alloc_trace+0x29d/0x340 mm/slub.c:2995
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
push_stack+0x86/0x710 kernel/bpf/verifier.c:1019
check_cond_jmp_op kernel/bpf/verifier.c:8815 [inline]
do_check+0x18d54/0x218b0 kernel/bpf/verifier.c:10882
do_check_common+0xc01/0x21a0 kernel/bpf/verifier.c:12865
do_check_main kernel/bpf/verifier.c:12931 [inline]
bpf_check+0x112e2/0x14720 kernel/bpf/verifier.c:13498
bpf_prog_load kernel/bpf/syscall.c:2274 [inline]
__sys_bpf+0x10923/0x11d80 kernel/bpf/syscall.c:4469
__do_sys_bpf kernel/bpf/syscall.c:4573 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4571 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4571
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1355 [inline]
free_pcp_prepare+0xc29/0xd20 mm/page_alloc.c:1406
free_unref_page_prepare mm/page_alloc.c:3341 [inline]
free_unref_page_list+0x118/0xad0 mm/page_alloc.c:3457
release_pages+0x18bb/0x1af0 mm/swap.c:972
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
tlb_flush_mmu+0x780/0x910 mm/mmu_gather.c:249
tlb_finish_mmu+0xcb/0x200 mm/mmu_gather.c:340
exit_mmap+0x404/0x7a0 mm/mmap.c:3204
__mmput+0x111/0x370 kernel/fork.c:1101
exit_mm+0x60a/0x770 kernel/exit.c:501
do_exit+0x6ae/0x2510 kernel/exit.c:812
do_group_exit+0x168/0x2d0 kernel/exit.c:922
__do_sys_exit_group+0x13/0x20 kernel/exit.c:933
__ia32_sys_exit_group+0x0/0x40 kernel/exit.c:931
__x64_sys_exit_group+0x37/0x40 kernel/exit.c:931
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Memory state around the buggy address:
ffff888021498c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888021498d00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888021498d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888021498e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888021498e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot
Aug 19, 2021, 4:32:23 PM8/19/21
to ebie...@xmission.com, hda...@sina.com, leg...@kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: d6d09a694205 Merge tag 'for-5.14-rc6-tag' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16c8081e300000
kernel config: https://syzkaller.appspot.com/x/.config?x=f61012d0b1cd846f
dashboard link: https://syzkaller.appspot.com/bug?extid=01985d7909f9468f013c
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d0ec1e300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1516c341300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01985d...@syzkaller.appspotmail.com
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004ca4cc
RBP: 00000000004ca4c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004ca4cc
R13: 00007fffffe0b62f R14: 00007f1054173400 R15: 0000000000022000
Write of size 8 at addr ffff888025b8ef80 by task syz-executor668/8707
CPU: 1 PID: 8707 Comm: syz-executor668 Not tainted 5.14.0-rc6-syzkaller #0
dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105
release_task+0x2d3/0x1590 kernel/exit.c:191
arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:865
Code: Unable to access opcode bytes at RIP 0x445a3f.
RSP: 002b:00007f1054173318 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffff2 RBX: 00000000004ca4c8 RCX: 0000000000445a69
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004ca4cc
RBP: 00000000004ca4c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004ca4cc
R13: 00007fffffe0b62f R14: 00007f1054173400 R15: 0000000000022000
Allocated by task 8441:
kmem_cache_alloc_trace+0x96/0x340 mm/slub.c:2986
set_cred_ucounts+0x220/0x2d0 kernel/cred.c:684
__sys_setresuid+0x6d5/0x920 kernel/sys.c:702
slab_free_hook mm/slub.c:1628 [inline]
slab_free_freelist_hook+0x1d8/0x290 mm/slub.c:1653
slab_free mm/slub.c:3213 [inline]
kfree+0xcf/0x2e0 mm/slub.c:4267
put_ucounts+0x15c/0x1a0 kernel/ucount.c:207
put_cred_rcu+0x221/0x400 kernel/cred.c:124
rcu_do_batch kernel/rcu/tree.c:2550 [inline]
rcu_core+0x906/0x14b0 kernel/rcu/tree.c:2785
__do_softirq+0x372/0x783 kernel/softirq.c:558
Last potentially related work creation:
kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:348
insert_work+0x54/0x400 kernel/workqueue.c:1332
__queue_work+0x928/0xc60 kernel/workqueue.c:1498
queue_work_on+0x111/0x200 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x283/0x470 kernel/umh.c:435
kobject_uevent_env+0x1337/0x1700 lib/kobject_uevent.c:618
device_add+0x1073/0x1790 drivers/base/core.c:3336
device_create_groups_vargs drivers/base/core.c:4014 [inline]
device_create+0x241/0x2d0 drivers/base/core.c:4056
vc_allocate+0x66a/0x780 drivers/tty/vt/vt.c:1157
con_install+0x9f/0x880 drivers/tty/vt/vt.c:3342
tty_driver_install_tty drivers/tty/tty_io.c:1315 [inline]
tty_init_dev+0xc6/0x4c0 drivers/tty/tty_io.c:1429
tty_open_by_driver drivers/tty/tty_io.c:2098 [inline]
tty_open+0x89a/0xdd0 drivers/tty/tty_io.c:2146
chrdev_open+0x53b/0x5f0 fs/char_dev.c:414
do_dentry_open+0x7cb/0x1020 fs/open.c:826
do_open fs/namei.c:3374 [inline]
path_openat+0x27e7/0x36b0 fs/namei.c:3507
do_filp_open+0x253/0x4d0 fs/namei.c:3534
do_sys_openat2+0x124/0x460 fs/open.c:1204
do_sys_open fs/open.c:1220 [inline]
__do_sys_open fs/open.c:1228 [inline]
__se_sys_open fs/open.c:1224 [inline]
__x64_sys_open+0x221/0x270 fs/open.c:1224
kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:348
insert_work+0x54/0x400 kernel/workqueue.c:1332
__queue_work+0x928/0xc60 kernel/workqueue.c:1498
queue_work_on+0x111/0x200 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x283/0x470 kernel/umh.c:435
kobject_uevent_env+0x1337/0x1700 lib/kobject_uevent.c:618
kobject_synth_uevent+0x3bf/0x900 lib/kobject_uevent.c:208
uevent_store+0x20/0x60 drivers/base/core.c:2372
kernfs_fop_write_iter+0x3b6/0x510 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2114 [inline]
new_sync_write fs/read_write.c:518 [inline]
vfs_write+0xa39/0xc90 fs/read_write.c:605
ksys_write+0x171/0x2a0 fs/read_write.c:658
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
prep_new_page mm/page_alloc.c:2436 [inline]
get_page_from_freelist+0x779/0xa30 mm/page_alloc.c:4169
__alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5391
alloc_page_interleave+0x22/0x1c0 mm/mempolicy.c:2119
alloc_slab_page mm/slub.c:1691 [inline]
allocate_slab+0xf1/0x540 mm/slub.c:1831
new_slab mm/slub.c:1894 [inline]
new_slab_objects mm/slub.c:2640 [inline]
___slab_alloc+0x1cf/0x350 mm/slub.c:2803
__slab_alloc mm/slub.c:2843 [inline]
slab_alloc_node mm/slub.c:2925 [inline]
slab_alloc mm/slub.c:2967 [inline]
kmem_cache_alloc_trace+0x29d/0x340 mm/slub.c:2984
kobject_uevent_env+0x1311/0x1700 lib/kobject_uevent.c:614
device_add+0x1073/0x1790 drivers/base/core.c:3336
__video_register_device+0x37fc/0x4580 drivers/media/v4l2-core/v4l2-dev.c:1036
video_register_device include/media/v4l2-dev.h:384 [inline]
vivid_create_devnodes drivers/media/test-drivers/vivid/vivid-core.c:1585 [inline]
vivid_create_instance+0x85df/0xac90 drivers/media/test-drivers/vivid/vivid-core.c:1946
vivid_probe+0x9a/0x140 drivers/media/test-drivers/vivid/vivid-core.c:2001
platform_probe+0x130/0x1b0 drivers/base/platform.c:1427
call_driver_probe+0x96/0x250 drivers/base/dd.c:517
really_probe+0x223/0x9b0 drivers/base/dd.c:595
__driver_probe_device+0x1f8/0x3e0 drivers/base/dd.c:747
page_owner free stack trace missing
Memory state around the buggy address:
ffff888025b8ee80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888025b8ef00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888025b8ef80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888025b8f000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888025b8f080: 00 00 00 00 00 fc fc fc fc fc fc fc fc 00 00 00
==================================================================
HEAD commit: d6d09a694205 Merge tag 'for-5.14-rc6-tag' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16c8081e300000
kernel config: https://syzkaller.appspot.com/x/.config?x=f61012d0b1cd846f
dashboard link: https://syzkaller.appspot.com/bug?extid=01985d7909f9468f013c
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d0ec1e300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1516c341300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01985d...@syzkaller.appspotmail.com
RBP: 00000000004ca4c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004ca4cc
R13: 00007fffffe0b62f R14: 00007f1054173400 R15: 0000000000022000
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
BUG: KASAN: use-after-free in atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
BUG: KASAN: use-after-free in dec_rlimit_ucounts+0x88/0x170 kernel/ucount.c:279
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
BUG: KASAN: use-after-free in atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
Write of size 8 at addr ffff888025b8ef80 by task syz-executor668/8707
CPU: 1 PID: 8707 Comm: syz-executor668 Not tainted 5.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
Call Trace:
dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105
print_address_description+0x66/0x3b0 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report+0x163/0x210 mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:135 [inline]
kasan_check_range+0x2b5/0x2f0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
dec_rlimit_ucounts+0x88/0x170 kernel/ucount.c:279
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report+0x163/0x210 mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:135 [inline]
kasan_check_range+0x2b5/0x2f0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic64_add_return include/asm-generic/atomic-instrumented.h:640 [inline]
atomic_long_add_return include/asm-generic/atomic-long.h:59 [inline]
release_task+0x2d3/0x1590 kernel/exit.c:191
exit_notify kernel/exit.c:699 [inline]
do_exit+0x1aa2/0x2510 kernel/exit.c:845
do_group_exit+0x168/0x2d0 kernel/exit.c:922
get_signal+0x16b0/0x2080 kernel/signal.c:2808
do_exit+0x1aa2/0x2510 kernel/exit.c:845
do_group_exit+0x168/0x2d0 kernel/exit.c:922
arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:865
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:209
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302
do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x445a69
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:209
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302
do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
Code: Unable to access opcode bytes at RIP 0x445a3f.
RSP: 002b:00007f1054173318 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffff2 RBX: 00000000004ca4c8 RCX: 0000000000445a69
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004ca4cc
RBP: 00000000004ca4c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004ca4cc
R13: 00007fffffe0b62f R14: 00007f1054173400 R15: 0000000000022000
Allocated by task 8441:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc+0xc4/0xf0 mm/kasan/common.c:513
kasan_kmalloc include/linux/kasan.h:264 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc+0xc4/0xf0 mm/kasan/common.c:513
kmem_cache_alloc_trace+0x96/0x340 mm/slub.c:2986
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
alloc_ucounts+0x1b1/0x5d0 kernel/ucount.c:173
kzalloc include/linux/slab.h:721 [inline]
set_cred_ucounts+0x220/0x2d0 kernel/cred.c:684
__sys_setresuid+0x6d5/0x920 kernel/sys.c:702
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 13:
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x3d/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0x109/0x150 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
kasan_set_track+0x3d/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0x109/0x150 mm/kasan/common.c:366
slab_free_hook mm/slub.c:1628 [inline]
slab_free_freelist_hook+0x1d8/0x290 mm/slub.c:1653
slab_free mm/slub.c:3213 [inline]
kfree+0xcf/0x2e0 mm/slub.c:4267
put_ucounts+0x15c/0x1a0 kernel/ucount.c:207
put_cred_rcu+0x221/0x400 kernel/cred.c:124
rcu_do_batch kernel/rcu/tree.c:2550 [inline]
rcu_core+0x906/0x14b0 kernel/rcu/tree.c:2785
__do_softirq+0x372/0x783 kernel/softirq.c:558
Last potentially related work creation:
kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:348
insert_work+0x54/0x400 kernel/workqueue.c:1332
__queue_work+0x928/0xc60 kernel/workqueue.c:1498
queue_work_on+0x111/0x200 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x283/0x470 kernel/umh.c:435
kobject_uevent_env+0x1337/0x1700 lib/kobject_uevent.c:618
device_add+0x1073/0x1790 drivers/base/core.c:3336
device_create_groups_vargs drivers/base/core.c:4014 [inline]
device_create+0x241/0x2d0 drivers/base/core.c:4056
vc_allocate+0x66a/0x780 drivers/tty/vt/vt.c:1157
con_install+0x9f/0x880 drivers/tty/vt/vt.c:3342
tty_driver_install_tty drivers/tty/tty_io.c:1315 [inline]
tty_init_dev+0xc6/0x4c0 drivers/tty/tty_io.c:1429
tty_open_by_driver drivers/tty/tty_io.c:2098 [inline]
tty_open+0x89a/0xdd0 drivers/tty/tty_io.c:2146
chrdev_open+0x53b/0x5f0 fs/char_dev.c:414
do_dentry_open+0x7cb/0x1020 fs/open.c:826
do_open fs/namei.c:3374 [inline]
path_openat+0x27e7/0x36b0 fs/namei.c:3507
do_filp_open+0x253/0x4d0 fs/namei.c:3534
do_sys_openat2+0x124/0x460 fs/open.c:1204
do_sys_open fs/open.c:1220 [inline]
__do_sys_open fs/open.c:1228 [inline]
__se_sys_open fs/open.c:1224 [inline]
__x64_sys_open+0x221/0x270 fs/open.c:1224
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Second to last potentially related work creation:
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:348
insert_work+0x54/0x400 kernel/workqueue.c:1332
__queue_work+0x928/0xc60 kernel/workqueue.c:1498
queue_work_on+0x111/0x200 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x283/0x470 kernel/umh.c:435
kobject_uevent_env+0x1337/0x1700 lib/kobject_uevent.c:618
kobject_synth_uevent+0x3bf/0x900 lib/kobject_uevent.c:208
uevent_store+0x20/0x60 drivers/base/core.c:2372
kernfs_fop_write_iter+0x3b6/0x510 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2114 [inline]
new_sync_write fs/read_write.c:518 [inline]
vfs_write+0xa39/0xc90 fs/read_write.c:605
ksys_write+0x171/0x2a0 fs/read_write.c:658
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff888025b8ef00
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
192-byte region [ffff888025b8ef00, ffff888025b8efc0)
The buggy address is located 128 bytes inside of
The buggy address belongs to the page:
page:ffffea000096e380 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25b8e
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00005dac80 0000000c0000000c ffff888011041a00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 9979944008, free_ts 0
page_owner tracks the page as allocated
prep_new_page mm/page_alloc.c:2436 [inline]
get_page_from_freelist+0x779/0xa30 mm/page_alloc.c:4169
__alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5391
alloc_page_interleave+0x22/0x1c0 mm/mempolicy.c:2119
alloc_slab_page mm/slub.c:1691 [inline]
allocate_slab+0xf1/0x540 mm/slub.c:1831
new_slab mm/slub.c:1894 [inline]
new_slab_objects mm/slub.c:2640 [inline]
___slab_alloc+0x1cf/0x350 mm/slub.c:2803
__slab_alloc mm/slub.c:2843 [inline]
slab_alloc_node mm/slub.c:2925 [inline]
slab_alloc mm/slub.c:2967 [inline]
kmem_cache_alloc_trace+0x29d/0x340 mm/slub.c:2984
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365
kzalloc include/linux/slab.h:721 [inline]
kobject_uevent_env+0x1311/0x1700 lib/kobject_uevent.c:614
device_add+0x1073/0x1790 drivers/base/core.c:3336
__video_register_device+0x37fc/0x4580 drivers/media/v4l2-core/v4l2-dev.c:1036
video_register_device include/media/v4l2-dev.h:384 [inline]
vivid_create_devnodes drivers/media/test-drivers/vivid/vivid-core.c:1585 [inline]
vivid_create_instance+0x85df/0xac90 drivers/media/test-drivers/vivid/vivid-core.c:1946
vivid_probe+0x9a/0x140 drivers/media/test-drivers/vivid/vivid-core.c:2001
platform_probe+0x130/0x1b0 drivers/base/platform.c:1427
call_driver_probe+0x96/0x250 drivers/base/dd.c:517
really_probe+0x223/0x9b0 drivers/base/dd.c:595
__driver_probe_device+0x1f8/0x3e0 drivers/base/dd.c:747
page_owner free stack trace missing
Memory state around the buggy address:
ffff888025b8ef00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888025b8ef80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888025b8f000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888025b8f080: 00 00 00 00 00 fc fc fc fc fc fc fc fc 00 00 00
==================================================================
Alexey Gladkov
Aug 20, 2021, 6:09:21 AM8/20/21
to syzbot, ebie...@xmission.com, hda...@sina.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com
{
...
/* don't need to get the RCU readlock here - the process is dead and
* can't be modifying its own credentials. But shut RCU-lockdep up */
rcu_read_lock();
dec_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
rcu_read_unlock();
...
}
It looks like the ucounts have been released before this in the put_cred_rcu().
Rgrds, legion
Eric W. Biederman
Aug 20, 2021, 9:49:00 AM8/20/21
to Alexey Gladkov, syzbot, hda...@sina.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com
After that in release_task there is:
put_task_struct_rcu_user
delayed_put_task_struct
put_task_struct
__put_task_struct
exit_creds
put_cred
__put_cred
put_cred_rcu
put_ucounts
So there very much should be a valid cred reference at that point.
Alexey Gladkov
Aug 23, 2021, 12:20:48 PM8/23/21
to Eric W. Biederman, syzbot, hda...@sina.com, linux-...@vger.kernel.org, syzkall...@googlegroups.com
syzkaller combined them in one thread misled me.
--
Rgrds, legion
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