netlink: 12 bytes leftover after parsing attributes in process `syz.0.0'. netlink: 'syz.0.0': attribute type 20 has an invalid length. netlink: 12 bytes leftover after parsing attributes in process `syz.0.0'. netlink: 'syz.0.0': attribute type 20 has an invalid length. Zero length message leads to an empty skb loop0: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.0/5349 is trying to acquire lock: ffff888052a228f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_free+0xc7/0x5f0 fs/hfsplus/bitmap.c:182 but task is already holding lock: ffff888052a26988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x290/0xbd0 fs/hfsplus/extents.c:573 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776 hfsplus_get_block+0x398/0x15d0 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x117/0x380 mm/filemap.c:2489 do_read_cache_folio+0x350/0x590 mm/filemap.c:4082 do_read_cache_page mm/filemap.c:4148 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4157 read_mapping_page include/linux/pagemap.h:1003 [inline] hfsplus_block_allocate+0xf3/0xc40 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa9a/0x1ba0 fs/hfsplus/extents.c:464 hfsplus_get_block+0x40a/0x15d0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_perform_write+0x2c5/0x900 mm/filemap.c:4300 generic_file_write_iter+0x117/0x550 mm/filemap.c:4443 __kernel_write_iter+0x428/0x910 fs/read_write.c:619 __kernel_write+0xef/0x150 fs/read_write.c:639 __dump_emit+0x206/0x310 fs/coredump.c:1220 elf_core_dump+0x2a87/0x3960 fs/binfmt_elf.c:2063 coredump_write+0x1121/0x18b0 fs/coredump.c:1049 do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x177/0x660 kernel/entry/common.c:196 exc_general_protection+0x171/0x1f0 arch/x86/kernel/traps.c:913 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:612 -> #0 (&sbi->alloc_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776 hfsplus_block_free+0xc7/0x5f0 fs/hfsplus/bitmap.c:182 hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:360 hfsplus_file_truncate+0x737/0xbd0 fs/hfsplus/extents.c:588 hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:286 notify_change+0xc1a/0xf40 fs/attr.c:546 do_truncate+0x1a4/0x220 fs/open.c:68 handle_truncate fs/namei.c:4235 [inline] do_open fs/namei.c:4632 [inline] path_openat+0x359d/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); *** DEADLOCK *** 3 locks held by syz.0.0/5349: #0: ffff8880361f8420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888052a26b78 (&sb->s_type->i_mutex_key#22){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline] #1: ffff888052a26b78 (&sb->s_type->i_mutex_key#22){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63 #2: ffff888052a26988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x290/0xbd0 fs/hfsplus/extents.c:573 stack backtrace: CPU: 0 UID: 0 PID: 5349 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776 hfsplus_block_free+0xc7/0x5f0 fs/hfsplus/bitmap.c:182 hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:360 hfsplus_file_truncate+0x737/0xbd0 fs/hfsplus/extents.c:588 hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:286 notify_change+0xc1a/0xf40 fs/attr.c:546 do_truncate+0x1a4/0x220 fs/open.c:68 handle_truncate fs/namei.c:4235 [inline] do_open fs/namei.c:4632 [inline] path_openat+0x359d/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f43d6f8f7c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f43d7d66038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f43d71e5fa0 RCX: 00007f43d6f8f7c9 RDX: 000000000000015f RSI: 6acc6bf18792a39a RDI: 00002000000001c0 RBP: 00007f43d7013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f43d71e6038 R14: 00007f43d71e5fa0 R15: 00007ffc9de9d598 hfsplus: unable to mark blocks free: error -5 hfsplus: can't free extent: start 134, count 1