============================================ WARNING: possible recursive locking detected 4.14.290-syzkaller #0 Not tainted -------------------------------------------- syz-executor.0/17942 is trying to acquire lock: ((fb_notifier_list).rwsem){++++}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] ((fb_notifier_list).rwsem){++++}, at: [] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] ((fb_notifier_list).rwsem){++++}, at: [] blocking_notifier_call_chain kernel/notifier.c:328 [inline] ((fb_notifier_list).rwsem){++++}, at: [] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325 but task is already holding lock: ((fb_notifier_list).rwsem){++++}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] ((fb_notifier_list).rwsem){++++}, at: [] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] ((fb_notifier_list).rwsem){++++}, at: [] blocking_notifier_call_chain kernel/notifier.c:328 [inline] ((fb_notifier_list).rwsem){++++}, at: [] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((fb_notifier_list).rwsem); lock((fb_notifier_list).rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor.0/17942: #0: (console_lock){+.+.}, at: [] do_fb_ioctl+0x81a/0xa70 drivers/video/fbdev/core/fbmem.c:1223 #1: (&fb_info->lock){+.+.}, at: [] lock_fb_info drivers/video/fbdev/core/fbmem.c:82 [inline] #1: (&fb_info->lock){+.+.}, at: [] do_fb_ioctl+0x824/0xa70 drivers/video/fbdev/core/fbmem.c:1224 #2: ((fb_notifier_list).rwsem){++++}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #2: ((fb_notifier_list).rwsem){++++}, at: [] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #2: ((fb_notifier_list).rwsem){++++}, at: [] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #2: ((fb_notifier_list).rwsem){++++}, at: [] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325 stack backtrace: CPU: 0 PID: 17942 Comm: syz-executor.0 Not tainted 4.14.290-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_deadlock_bug kernel/locking/lockdep.c:1800 [inline] check_deadlock kernel/locking/lockdep.c:1847 [inline] validate_chain kernel/locking/lockdep.c:2448 [inline] __lock_acquire.cold+0x180/0x97c kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 down_read+0x36/0x80 kernel/locking/rwsem.c:24 __blocking_notifier_call_chain kernel/notifier.c:316 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325 fb_set_var+0xbc8/0xdc0 drivers/video/fbdev/core/fbmem.c:1065 fbcon_switch+0x3d9/0x19e0 drivers/video/fbdev/core/fbcon.c:2066 redraw_screen+0x32c/0x790 drivers/tty/vt/vt.c:689 fbcon_blank+0x986/0xd50 drivers/video/fbdev/core/fbcon.c:2204 do_unblank_screen+0x1fd/0x4e0 drivers/tty/vt/vt.c:3954 fbcon_fb_blanked drivers/video/fbdev/core/fbcon.c:2933 [inline] fbcon_event_notify+0x1445/0x1760 drivers/video/fbdev/core/fbcon.c:3051 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x79/0x90 kernel/notifier.c:325 fb_blank+0x14c/0x190 drivers/video/fbdev/core/fbmem.c:1093 do_fb_ioctl+0x894/0xa70 drivers/video/fbdev/core/fbmem.c:1229 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1253 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fb817597279 RSP: 002b:00007fb815f0c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb8176a9f80 RCX: 00007fb817597279 RDX: 0000000000000000 RSI: 0000000000004611 RDI: 0000000000000004 RBP: 00007fb8175f1189 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdb505324f R14: 00007fb815f0c300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 18625 Comm: syz-executor.2 Not tainted 4.14.290-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x2c1/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] vc_do_resize+0x2cb/0xe40 drivers/tty/vt/vt.c:908 fbcon_modechanged+0x490/0x8d0 drivers/video/fbdev/core/fbcon.c:2659 fbcon_event_notify+0x107/0x1760 drivers/video/fbdev/core/fbcon.c:3021 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x79/0x90 kernel/notifier.c:325 fb_set_var+0xbc8/0xdc0 drivers/video/fbdev/core/fbmem.c:1065 do_fb_ioctl+0x36d/0xa70 drivers/video/fbdev/core/fbmem.c:1138 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1253 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f1cd34b8279 RSP: 002b:00007f1cd1e2d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1cd35caf80 RCX: 00007f1cd34b8279 RDX: 0000000020000100 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 00007f1cd1e2d1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffeadd4361f R14: 00007f1cd1e2d300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 19899 Comm: syz-executor.4 Not tainted 4.14.290-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc+0x28e/0x3c0 mm/slab.c:3550 getname_flags+0xc8/0x550 fs/namei.c:138 do_sys_open+0x1ce/0x410 fs/open.c:1075 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fe2b04ca279 RSP: 002b:00007fe2aee3f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe2b05dcf80 RCX: 00007fe2b04ca279 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: ffffffffffffff9c RBP: 00007fe2aee3f1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe4291d20f R14: 00007fe2aee3f300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 19916 Comm: syz-executor.4 Not tainted 4.14.290-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2898 [inline] prepare_alloc_pages mm/page_alloc.c:4131 [inline] __alloc_pages_nodemask+0x22c/0x2720 mm/page_alloc.c:4179 __alloc_pages include/linux/gfp.h:484 [inline] __alloc_pages_node include/linux/gfp.h:497 [inline] kmem_getpages mm/slab.c:1419 [inline] cache_grow_begin+0x91/0x700 mm/slab.c:2676 cache_alloc_refill+0x273/0x350 mm/slab.c:3043 ____cache_alloc mm/slab.c:3125 [inline] __do_cache_alloc mm/slab.c:3347 [inline] slab_alloc mm/slab.c:3382 [inline] kmem_cache_alloc+0x333/0x3c0 mm/slab.c:3550 getname_flags+0xc8/0x550 fs/namei.c:138