bisecting fixing commit since eb575cd5d7f60241d016fdd13a9e86d962093c9b building syzkaller on aba2b2fb3544d9e42991237c13d8cada421deda5 testing commit eb575cd5d7f60241d016fdd13a9e86d962093c9b compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 56f826695b38c41304966f6c38a8eba0ac19bd14a1c947ef069277c9cc3f3308 run #0: crashed: KASAN: use-after-free Read in __isofs_iget run #1: crashed: KASAN: use-after-free Read in __isofs_iget run #2: crashed: KASAN: out-of-bounds Read in __isofs_iget run #3: crashed: KASAN: use-after-free Read in __isofs_iget run #4: crashed: KASAN: use-after-free Read in __isofs_iget run #5: crashed: KASAN: use-after-free Read in __isofs_iget run #6: crashed: KASAN: use-after-free Read in __isofs_iget run #7: crashed: KASAN: use-after-free Read in __isofs_iget run #8: crashed: KASAN: out-of-bounds Read in __isofs_iget run #9: crashed: KASAN: use-after-free Read in __isofs_iget run #10: crashed: KASAN: use-after-free Read in __isofs_iget run #11: crashed: KASAN: use-after-free Read in __isofs_iget run #12: crashed: KASAN: use-after-free Read in __isofs_iget run #13: crashed: KASAN: use-after-free Read in __isofs_iget run #14: crashed: KASAN: use-after-free Read in __isofs_iget run #15: crashed: KASAN: slab-out-of-bounds Read in __isofs_iget run #16: crashed: KASAN: use-after-free Read in __isofs_iget run #17: crashed: KASAN: use-after-free Read in __isofs_iget run #18: crashed: KASAN: use-after-free Read in __isofs_iget run #19: crashed: KASAN: use-after-free Read in __isofs_iget testing current HEAD 3f8a27f9e27bd78604c0709224cec0ec85a8b106 testing commit 3f8a27f9e27bd78604c0709224cec0ec85a8b106 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 5714204f43fdec3a1eaf0d1e571ee5591dfe8aaa7d2e47e8b50f44ef3ce157fa all runs: crashed: KASAN: use-after-free Read in __isofs_iget revisions tested: 2, total time: 27m30.726665969s (build: 19m46.646081753s, test: 7m16.381401032s) the crash still happens on HEAD commit msg: Linux 4.19.211 crash: KASAN: use-after-free Read in __isofs_iget wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 ================================================================== BUG: KASAN: use-after-free in isofs_read_inode fs/isofs/inode.c:1354 [inline] BUG: KASAN: use-after-free in __isofs_iget+0x19b0/0x2010 fs/isofs/inode.c:1554 Read of size 1 at addr ffff888080d7b015 by task syz-executor.4/9942 CPU: 0 PID: 9942 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 print_address_description.cold.6+0x9/0x211 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:396 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 isofs_read_inode fs/isofs/inode.c:1354 [inline] __isofs_iget+0x19b0/0x2010 fs/isofs/inode.c:1554 isofs_iget fs/isofs/isofs.h:133 [inline] isofs_export_iget.part.1+0x12/0x80 fs/isofs/export.c:29 isofs_export_iget fs/isofs/export.c:170 [inline] isofs_fh_to_dentry+0xc7/0x110 fs/isofs/export.c:170 exportfs_decode_fh+0x119/0x640 fs/exportfs/expfs.c:433 do_handle_to_path fs/fhandle.c:152 [inline] handle_to_path fs/fhandle.c:207 [inline] do_handle_open+0x26c/0x5d0 fs/fhandle.c:223 __do_sys_open_by_handle_at fs/fhandle.c:265 [inline] __se_sys_open_by_handle_at fs/fhandle.c:256 [inline] __x64_sys_open_by_handle_at+0x71/0xb0 fs/fhandle.c:256 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665d9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc2a30aa188 EFLAGS: 00000246 ORIG_RAX: 0000000000000130 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000005 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffdfb7e1f5f R14: 00007fc2a30aa300 R15: 0000000000022000 The buggy address belongs to the page: page:ffffea0002035ec0 count:0 mapcount:0 mapping:0000000000000000 index:0x1 flags: 0xfff00000000000() raw: 00fff00000000000 ffffea000204d9c8 ffffea00023b23c8 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888080d7af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888080d7af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888080d7b000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888080d7b080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888080d7b100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Bluetooth: hci1: command 0x0419 tx timeout Bluetooth: hci4: command 0x0419 tx timeout