Re: [syzbot] possible deadlock in filemap_fault
From: syzbot
Date: Tue Dec 06 2022 - 13:10:53 EST
syzbot has found a reproducer for the following issue on:
HEAD commit: a5541c0811a0 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=176e216b880000
kernel config: https://syzkaller.appspot.com/x/.config?x=cbd4e584773e9397
dashboard link: https://syzkaller.appspot.com/bug?extid=7736960b837908f3a81d
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17289a2f880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15215fc3880000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4b7702208fb9/disk-a5541c08.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9ec0153ec051/vmlinux-a5541c08.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6f8725ad290a/Image-a5541c08.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e6f9575381c5/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7736960b837908f3a81d@xxxxxxxxxxxxxxxxxxxxxxxxx
exfat: Deprecated parameter 'utf8'
exFAT-fs (loop0): failed to load upcase table (idx : 0x00010000, chksum : 0x207d53fc, utbl_chksum : 0xe619d30d)
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc8-syzkaller-33330-ga5541c0811a0 #0 Not tainted
------------------------------------------------------
syz-executor581/3072 is trying to acquire lock:
ffff0000caee1060 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
ffff0000caee1060 (mapping.invalidate_lock#3){.+.+}-{3:3}, at: filemap_fault+0x104/0x7fc mm/filemap.c:3127
but task is already holding lock:
ffff0000c02520c8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
ffff0000c02520c8 (&mm->mmap_lock){++++}-{3:3}, at: do_page_fault+0x1ec/0x79c arch/arm64/mm/fault.c:589
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&mm->mmap_lock){++++}-{3:3}:
__might_fault+0x7c/0xb4 mm/memory.c:5645
filldir64+0x1e8/0x574 fs/readdir.c:335
dir_emit_dot include/linux/fs.h:3569 [inline]
dir_emit_dots include/linux/fs.h:3580 [inline]
exfat_iterate+0xd4/0xcb4 fs/exfat/dir.c:231
iterate_dir+0x114/0x28c
__do_sys_getdents64 fs/readdir.c:369 [inline]
__se_sys_getdents64 fs/readdir.c:354 [inline]
__arm64_sys_getdents64+0x80/0x204 fs/readdir.c:354
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
-> #1 (&sbi->s_lock){+.+.}-{3:3}:
__mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
exfat_get_block+0x6c/0x9ec fs/exfat/inode.c:282
do_mpage_readpage+0x474/0xd38 fs/mpage.c:208
mpage_readahead+0xf0/0x1b8 fs/mpage.c:361
exfat_readahead+0x28/0x38 fs/exfat/inode.c:345
read_pages+0x8c/0x4f0 mm/readahead.c:161
page_cache_ra_unbounded+0x374/0x400 mm/readahead.c:270
do_page_cache_ra mm/readahead.c:300 [inline]
page_cache_ra_order+0x348/0x380 mm/readahead.c:560
ondemand_readahead+0x340/0x720 mm/readahead.c:682
page_cache_sync_ra+0xc4/0xdc mm/readahead.c:709
page_cache_sync_readahead include/linux/pagemap.h:1213 [inline]
filemap_get_pages+0x118/0x598 mm/filemap.c:2581
filemap_read+0x14c/0x6f4 mm/filemap.c:2675
generic_file_read_iter+0x6c/0x25c mm/filemap.c:2821
call_read_iter include/linux/fs.h:2193 [inline]
aio_read+0x170/0x254 fs/aio.c:1560
__io_submit_one+0x218/0x5e4
io_submit_one+0x2c4/0x4bc fs/aio.c:2019
__do_sys_io_submit+0x16c/0x2ac fs/aio.c:2078
__se_sys_io_submit fs/aio.c:2048 [inline]
__arm64_sys_io_submit+0x24/0x34 fs/aio.c:2048
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
-> #0 (mapping.invalidate_lock#3){.+.+}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668
down_read+0x5c/0x78 kernel/locking/rwsem.c:1509
filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
filemap_fault+0x104/0x7fc mm/filemap.c:3127
__do_fault+0x60/0x358 mm/memory.c:4202
do_read_fault mm/memory.c:4553 [inline]
do_fault+0x338/0x550 mm/memory.c:4682
handle_pte_fault mm/memory.c:4954 [inline]
__handle_mm_fault mm/memory.c:5096 [inline]
handle_mm_fault+0x78c/0xa48 mm/memory.c:5217
__do_page_fault arch/arm64/mm/fault.c:508 [inline]
do_page_fault+0x428/0x79c arch/arm64/mm/fault.c:608
do_translation_fault+0x78/0x194 arch/arm64/mm/fault.c:691
do_mem_abort+0x54/0x130 arch/arm64/mm/fault.c:827
el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367
el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:427
el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:579
do_strncpy_from_user lib/strncpy_from_user.c:41 [inline]
strncpy_from_user+0x1a8/0x3d8 lib/strncpy_from_user.c:139
getname_flags+0x84/0x278 fs/namei.c:150
getname+0x28/0x38 fs/namei.c:218
do_sys_openat2+0x78/0x22c fs/open.c:1304
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1337
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
other info that might help us debug this:
Chain exists of:
mapping.invalidate_lock#3 --> &sbi->s_lock --> &mm->mmap_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&mm->mmap_lock);
lock(&sbi->s_lock);
lock(&mm->mmap_lock);
lock(mapping.invalidate_lock#3);
*** DEADLOCK ***
1 lock held by syz-executor581/3072:
#0: ffff0000c02520c8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff0000c02520c8 (&mm->mmap_lock){++++}-{3:3}, at: do_page_fault+0x1ec/0x79c arch/arm64/mm/fault.c:589
stack backtrace:
CPU: 0 PID: 3072 Comm: syz-executor581 Not tainted 6.1.0-rc8-syzkaller-33330-ga5541c0811a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
Call trace:
dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:163
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2055
check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668
down_read+0x5c/0x78 kernel/locking/rwsem.c:1509
filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
filemap_fault+0x104/0x7fc mm/filemap.c:3127
__do_fault+0x60/0x358 mm/memory.c:4202
do_read_fault mm/memory.c:4553 [inline]
do_fault+0x338/0x550 mm/memory.c:4682
handle_pte_fault mm/memory.c:4954 [inline]
__handle_mm_fault mm/memory.c:5096 [inline]
handle_mm_fault+0x78c/0xa48 mm/memory.c:5217
__do_page_fault arch/arm64/mm/fault.c:508 [inline]
do_page_fault+0x428/0x79c arch/arm64/mm/fault.c:608
do_translation_fault+0x78/0x194 arch/arm64/mm/fault.c:691
do_mem_abort+0x54/0x130 arch/arm64/mm/fault.c:827
el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367
el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:427
el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:579
do_strncpy_from_user lib/strncpy_from_user.c:41 [inline]
strncpy_from_user+0x1a8/0x3d8 lib/strncpy_from_user.c:139
getname_flags+0x84/0x278 fs/namei.c:150
getname+0x28/0x38 fs/namei.c:218
do_sys_openat2+0x78/0x22c fs/open.c:1304
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1337
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584