====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.527/6230 is trying to acquire lock: ffff88802415f978 (&p->frag_sem){.+.+}-{3:3}, at: __configfs_open_file+0xd5/0x7d0 fs/configfs/file.c:304 but task is already holding lock: ffff888079c1e9c0 (&iint_mutex_key[depth]){+.+.}-{3:3}, at: process_measurement+0x724/0x1c20 security/integrity/ima/ima_main.c:261 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&iint_mutex_key[depth]){+.+.}-{3:3}: __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 process_measurement+0x724/0x1c20 security/integrity/ima/ima_main.c:261 ima_file_check+0xc7/0x110 security/integrity/ima/ima_main.c:533 do_open fs/namei.c:3618 [inline] path_openat+0x27cf/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #2 (sb_writers#3){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1811 [inline] sb_start_write+0x4f/0x1c0 include/linux/fs.h:1881 mnt_want_write+0x3d/0x90 fs/namespace.c:386 open_last_lookups fs/namei.c:3529 [inline] path_openat+0x795/0x2fb0 fs/namei.c:3747 do_filp_open+0x1df/0x400 fs/namei.c:3777 file_open_name fs/open.c:1200 [inline] filp_open+0x17c/0x1e0 fs/open.c:1220 fsg_lun_open+0x63/0xee0 drivers/usb/gadget/function/storage_common.c:193 fsg_store_file+0x1a5/0x530 drivers/usb/gadget/function/storage_common.c:454 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x748/0xd70 fs/read_write.c:594 ksys_write+0x153/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (&common->filesem){+.+.}-{3:3}: down_write+0x38/0x60 kernel/locking/rwsem.c:1551 fsg_store_file+0x174/0x530 drivers/usb/gadget/function/storage_common.c:451 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x748/0xd70 fs/read_write.c:594 ksys_write+0x153/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&p->frag_sem){.+.+}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 __configfs_open_file+0xd5/0x7d0 fs/configfs/file.c:304 do_dentry_open+0x7f7/0xf90 fs/open.c:826 vfs_open fs/open.c:958 [inline] dentry_open+0xc6/0x120 fs/open.c:974 ima_calc_file_hash+0x18c/0x1940 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x335/0x7e0 security/integrity/ima/ima_api.c:255 process_measurement+0x1185/0x1c20 security/integrity/ima/ima_main.c:351 ima_file_check+0xc7/0x110 security/integrity/ima/ima_main.c:533 do_open fs/namei.c:3618 [inline] path_openat+0x27cf/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &p->frag_sem --> sb_writers#3 --> &iint_mutex_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&iint_mutex_key[depth]); lock(sb_writers#3); lock(&iint_mutex_key[depth]); lock(&p->frag_sem); *** DEADLOCK *** 1 lock held by syz.6.527/6230: #0: ffff888079c1e9c0 (&iint_mutex_key[depth]){+.+.}-{3:3}, at: process_measurement+0x724/0x1c20 security/integrity/ima/ima_main.c:261 stack backtrace: CPU: 0 PID: 6230 Comm: syz.6.527 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 __configfs_open_file+0xd5/0x7d0 fs/configfs/file.c:304 do_dentry_open+0x7f7/0xf90 fs/open.c:826 vfs_open fs/open.c:958 [inline] dentry_open+0xc6/0x120 fs/open.c:974 ima_calc_file_hash+0x18c/0x1940 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x335/0x7e0 security/integrity/ima/ima_api.c:255 process_measurement+0x1185/0x1c20 security/integrity/ima/ima_main.c:351 ima_file_check+0xc7/0x110 security/integrity/ima/ima_main.c:533 do_open fs/namei.c:3618 [inline] path_openat+0x27cf/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9491fb4019 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f949020c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f949223bfa0 RCX: 00007f9491fb4019 RDX: 0000000000000001 RSI: 00002000000001c0 RDI: ffffffffffffff9c RBP: 00007f949204b00c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f949223c038 R14: 00007f949223bfa0 R15: 00007ffe5f815b98