====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc4-syzkaller-00025-g3a93e40326c8 #0 Not tainted ------------------------------------------------------ syz-executor.4/16256 is trying to acquire lock: ffff8880188b4d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline] ffff8880188b4d58 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0xa51/0x1230 arch/x86/mm/fault.c:1358 but task is already holding lock: ffff88804e7aa0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x111/0xb40 fs/exfat/dir.c:232 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sbi->s_lock#2){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 exfat_get_block+0x18d/0x16e0 fs/exfat/inode.c:280 do_mpage_readpage+0x768/0x1960 fs/mpage.c:208 mpage_readahead+0x344/0x580 fs/mpage.c:356 read_pages+0x1a2/0xd40 mm/readahead.c:161 page_cache_ra_unbounded+0x477/0x5e0 mm/readahead.c:270 do_page_cache_ra mm/readahead.c:300 [inline] page_cache_ra_order+0x6ec/0xa00 mm/readahead.c:560 ondemand_readahead+0x6b3/0x1080 mm/readahead.c:682 page_cache_sync_ra+0x1c9/0x200 mm/readahead.c:709 page_cache_sync_readahead include/linux/pagemap.h:1214 [inline] filemap_get_pages+0x28d/0x1620 mm/filemap.c:2598 filemap_read+0x35e/0xc70 mm/filemap.c:2693 generic_file_read_iter+0x3ad/0x5b0 mm/filemap.c:2840 call_read_iter include/linux/fs.h:1845 [inline] generic_file_splice_read+0x182/0x4b0 fs/splice.c:402 do_splice_to+0x1b9/0x240 fs/splice.c:885 splice_direct_to_actor+0x2ab/0x8a0 fs/splice.c:956 do_splice_direct+0x1ab/0x280 fs/splice.c:1065 do_sendfile+0xb19/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (mapping.invalidate_lock#5){.+.+}-{3:3}: down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 filemap_invalidate_lock_shared include/linux/fs.h:813 [inline] filemap_fault+0xb99/0x2450 mm/filemap.c:3274 __do_fault+0x107/0x600 mm/memory.c:4141 do_read_fault mm/memory.c:4492 [inline] do_fault mm/memory.c:4621 [inline] handle_pte_fault mm/memory.c:4909 [inline] __handle_mm_fault+0x24f3/0x3e60 mm/memory.c:5051 handle_mm_fault+0x2ba/0x9c0 mm/memory.c:5197 faultin_page mm/gup.c:925 [inline] __get_user_pages+0x4da/0xf30 mm/gup.c:1147 populate_vma_page_range+0x2df/0x420 mm/gup.c:1543 __mm_populate+0x105/0x3b0 mm/gup.c:1652 mm_populate include/linux/mm.h:3026 [inline] vm_mmap_pgoff+0x201/0x280 mm/util.c:547 ksys_mmap_pgoff+0x41f/0x5a0 mm/mmap.c:1410 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 mmap_read_lock include/linux/mmap_lock.h:117 [inline] do_user_addr_fault+0xa51/0x1230 arch/x86/mm/fault.c:1358 handle_page_fault arch/x86/mm/fault.c:1498 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1554 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 filldir+0x1ec/0x680 fs/readdir.c:253 dir_emit_dot include/linux/fs.h:3144 [inline] dir_emit_dots include/linux/fs.h:3155 [inline] exfat_iterate+0x56b/0xb40 fs/exfat/dir.c:235 iterate_dir+0x1fd/0x6f0 fs/readdir.c:67 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents fs/readdir.c:271 [inline] __x64_sys_getdents+0x13e/0x2c0 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &mm->mmap_lock --> mapping.invalidate_lock#5 --> &sbi->s_lock#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_lock#2); lock(mapping.invalidate_lock#5); lock(&sbi->s_lock#2); lock(&mm->mmap_lock); *** DEADLOCK *** 3 locks held by syz-executor.4/16256: #0: ffff888020567168 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe7/0x100 fs/file.c:1047 #1: ffff888036a11a30 (&sb->s_type->i_mutex_key#28){++++}-{3:3}, at: iterate_dir+0x504/0x6f0 fs/readdir.c:57 #2: ffff88804e7aa0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x111/0xb40 fs/exfat/dir.c:232 stack backtrace: CPU: 1 PID: 16256 Comm: syz-executor.4 Not tainted 6.3.0-rc4-syzkaller-00025-g3a93e40326c8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 mmap_read_lock include/linux/mmap_lock.h:117 [inline] do_user_addr_fault+0xa51/0x1230 arch/x86/mm/fault.c:1358 handle_page_fault arch/x86/mm/fault.c:1498 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1554 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:filldir+0x1ec/0x680 fs/readdir.c:253 Code: 48 89 c6 48 89 44 24 20 e8 21 b2 9b ff 48 8b 44 24 20 49 39 c6 0f 87 44 02 00 00 e8 1e b6 9b ff 0f 01 cb 0f ae e8 48 8b 04 24 <49> 89 46 08 e8 0b b6 9b ff 4c 8b 74 24 38 48 8b 7c 24 10 49 89 3e RSP: 0018:ffffc90004a0fc00 EFLAGS: 00050212 RAX: 0000000000000000 RBX: ffffc90004a0fe98 RCX: ffffc9000c392000 RDX: 0000000000040000 RSI: ffffffff81e642e2 RDI: 0000000000000006 RBP: 0000000000000001 R08: 0000000000000006 R09: 0000000020001fc0 R10: 00007fffffffefe8 R11: 0000000000000002 R12: 0000000000000018 R13: ffffffff8a65a5c0 R14: 0000000020001fc0 R15: 0000000000000018 dir_emit_dot include/linux/fs.h:3144 [inline] dir_emit_dots include/linux/fs.h:3155 [inline] exfat_iterate+0x56b/0xb40 fs/exfat/dir.c:235 iterate_dir+0x1fd/0x6f0 fs/readdir.c:67 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents fs/readdir.c:271 [inline] __x64_sys_getdents+0x13e/0x2c0 fs/readdir.c:271 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f639448c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6395274168 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f63945abf80 RCX: 00007f639448c0f9 RDX: 00000000000000b8 RSI: 0000000020001fc0 RDI: 0000000000000006 RBP: 00007f63944e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc6661e1ff R14: 00007f6395274300 R15: 0000000000022000 exFAT-fs (loop4): error, invalid access to FAT (entry 0x00000005) bogus content (0x927a7ff5) exFAT-fs (loop4): Filesystem has been set read-only ---------------- Code disassembly (best guess): 0: 48 89 c6 mov %rax,%rsi 3: 48 89 44 24 20 mov %rax,0x20(%rsp) 8: e8 21 b2 9b ff callq 0xff9bb22e d: 48 8b 44 24 20 mov 0x20(%rsp),%rax 12: 49 39 c6 cmp %rax,%r14 15: 0f 87 44 02 00 00 ja 0x25f 1b: e8 1e b6 9b ff callq 0xff9bb63e 20: 0f 01 cb stac 23: 0f ae e8 lfence 26: 48 8b 04 24 mov (%rsp),%rax * 2a: 49 89 46 08 mov %rax,0x8(%r14) <-- trapping instruction 2e: e8 0b b6 9b ff callq 0xff9bb63e 33: 4c 8b 74 24 38 mov 0x38(%rsp),%r14 38: 48 8b 7c 24 10 mov 0x10(%rsp),%rdi 3d: 49 89 3e mov %rdi,(%r14)