============================================ WARNING: possible recursive locking detected 4.14.290-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/5013 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.3/5013: #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: 5013 Comm: syz-executor.3 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: 0033:0x7fbf67c34279 RSP: 002b:00007fbf665a9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbf67d46f80 RCX: 00007fbf67c34279 RDX: 0000000000000000 RSI: 0000000000004611 RDI: 0000000000000003 RBP: 00007fbf67c8e189 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc298c61f R14: 00007fbf665a9300 R15: 0000000000022000 base_sock_release(ffff8880866b6b00) sk=ffff8880a98a0a40 base_sock_release(ffff88807bc44040) sk=ffff8880a3b8cc00 base_sock_release(ffff888073cb5080) sk=ffff88809c6b0900 base_sock_release(ffff888073cb5500) sk=ffff8880ab539500 base_sock_release(ffff88807a3b1a40) sk=ffff888095356440 base_sock_release(ffff888074e30b00) sk=ffff8880a5038540 base_sock_release(ffff888087945040) sk=ffff88809597d680 base_sock_release(ffff888074a40100) sk=ffff8880a9613240 base_sock_release(ffff8880759f7180) sk=ffff88809463e440 base_sock_release(ffff888088439540) sk=ffff88809463ecc0 base_sock_release(ffff8880751c9a40) sk=ffff888094d71700 base_sock_release(ffff8880751c95c0) sk=ffff8880b48c8480 base_sock_release(ffff88807a12e580) sk=ffff8880b2a66900 base_sock_release(ffff88807a12ea00) sk=ffff8880b2c6a300 base_sock_release(ffff888087a1e9c0) sk=ffff88809d9c51c0 base_sock_release(ffff88809f3019c0) sk=ffff88809d9c40c0 base_sock_release(ffff88809f301540) sk=ffff8880a90aeec0 base_sock_release(ffff888073ec4580) sk=ffff88809d76a480 base_sock_release(ffff888087a44040) sk=ffff8880b41d04c0 base_sock_release(ffff888073c9a580) sk=ffff8880afba2940 base_sock_release(ffff888073c9f5c0) sk=ffff8880af2568c0 base_sock_release(ffff888074dfda80) sk=ffff8880a213a640 base_sock_release(ffff888074dfd180) sk=ffff8880a53581c0 base_sock_release(ffff88808d3ae000) sk=ffff8880b550eb80 base_sock_release(ffff888087b4b480) sk=ffff8880806994c0 base_sock_release(ffff888073cae100) sk=ffff888094d70600 base_sock_release(ffff888087556640) sk=ffff88809dbdae00 base_sock_release(ffff88807501c000) sk=ffff88809ddb9200 base_sock_release(ffff888074e87140) sk=ffff88809fdec240 base_sock_release(ffff888074b18a80) sk=ffff8880ab881380 base_sock_release(ffff888073f8f5c0) sk=ffff8880ab880280 base_sock_release(ffff88807532c200) sk=ffff8880b4b841c0 base_sock_release(ffff888073c61980) sk=ffff88809e586cc0 base_sock_release(ffff888073c61080) sk=ffff8880a37f6200 base_sock_release(ffff888073d98100) sk=ffff8880a37f7300 base_sock_release(ffff888073f80a00) sk=ffff88809677e4c0 base_sock_release(ffff88807a178580) sk=ffff8880a4d068c0 base_sock_release(ffff88807501c900) sk=ffff888095162cc0 base_sock_release(ffff888074bd4900) sk=ffff8880af3b4d00 base_sock_release(ffff88808871c140) sk=ffff888094c8d540 base_sock_release(ffff8880a4a43500) sk=ffff8880b3f66cc0 base_sock_release(ffff88807f042640) sk=ffff8880a5006e80 base_sock_release(ffff88807f042ac0) sk=ffff88809ae57440 base_sock_release(ffff888073ea6000) sk=ffff88807c1b6a80 base_sock_release(ffff888074f8b200) sk=ffff88807c1b6200 base_sock_release(ffff888087ac6100) sk=ffff8880b467b600 base_sock_release(ffff88807497d540) sk=ffff8880b0b1a3c0 base_sock_release(ffff888074edfac0) sk=ffff88809d70c2c0 base_sock_release(ffff888074aa2680) sk=ffff88807f4e6cc0 base_sock_release(ffff888075bae200) sk=ffff88809cbca000 base_sock_release(ffff888075bae680) sk=ffff88807ec4cd80 base_sock_release(ffff8880b1e17940) sk=ffff888090bbcc80 base_sock_release(ffff88807a09e480) sk=ffff88809b77e240 base_sock_release(ffff8880886e4a00) sk=ffff888086ad61c0 base_sock_release(ffff88807a22d540) sk=ffff88807eceee00 base_sock_release(ffff8880866e4080) sk=ffff888094730980 base_sock_release(ffff88807a3da9c0) sk=ffff888098061700 base_sock_release(ffff8880866de9c0) sk=ffff88808fa5e640 base_sock_release(ffff88807f0e4640) sk=ffff88809a29ac00 base_sock_release(ffff888074897900) sk=ffff8880a9d2ad80 base_sock_release(ffff888074823980) sk=ffff8880aa7b20c0 base_sock_release(ffff888073f93480) sk=ffff8880947ea180 base_sock_release(ffff8880748f2500) sk=ffff88807cb90200 base_sock_release(ffff88808798a9c0) sk=ffff8880a5006600 base_sock_release(ffff88808798a0c0) sk=ffff8880b3206180 base_sock_release(ffff8880748f2080) sk=ffff8880b3207280 base_sock_release(ffff8880b1de1100) sk=ffff88809ad6c600 base_sock_release(ffff88807ce4aac0) sk=ffff88809fe1e600 base_sock_release(ffff88807f25b500) sk=ffff88809180cb40 base_sock_release(ffff888074d9e5c0) sk=ffff88809548b540 base_sock_release(ffff888088605180) sk=ffff8880b1a365c0 base_sock_release(ffff88807bdf71c0) sk=ffff8880b3c44140 base_sock_release(ffff8880751cea40) sk=ffff88808d443100 base_sock_release(ffff8880885fc9c0) sk=ffff888090979100 base_sock_release(ffff88807496a500) sk=ffff8880b55ab180 nla_parse: 219 callbacks suppressed netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. base_sock_release(ffff888075a2ea40) sk=ffff8880ab9a2880 base_sock_release(ffff888074fe5580) sk=ffff88807c65ab40 base_sock_release(ffff888074fe5a00) sk=ffff888094e3d2c0 base_sock_release(ffff888087b561c0) sk=ffff88809f788940 base_sock_release(ffff88807dd72680) sk=ffff88807d250380 nla_parse: 439 callbacks suppressed netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.1'.