bisecting fixing commit since eb575cd5d7f60241d016fdd13a9e86d962093c9b building syzkaller on aba2b2fb3544d9e42991237c13d8cada421deda5 testing commit eb575cd5d7f60241d016fdd13a9e86d962093c9b with gcc (GCC) 8.4.1 20210217 kernel signature: 00ed1223f6901b13916516608c083179a1de49daab93fab3ebe3790ef656f70a 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: use-after-free 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: use-after-free 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: out-of-bounds 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: use-after-free 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 fcfbdfe9626edd5bf00c732e093eed249ecdbfa1 testing commit fcfbdfe9626edd5bf00c732e093eed249ecdbfa1 with gcc (GCC) 8.4.1 20210217 kernel signature: 83afca34e3db4089c55a1db6ae7049d5ffdb02b5b1ca2e40c8bec82d499234f5 all runs: crashed: KASAN: use-after-free Read in __isofs_iget revisions tested: 2, total time: 26m39.126553036s (build: 18m26.75921722s, test: 7m43.356321489s) the crash still happens on HEAD commit msg: Linux 4.19.197 crash: KASAN: use-after-free Read in __isofs_iget IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 ================================================================== BUG: KASAN: use-after-free in isofs_read_inode fs/isofs/inode.c:1355 [inline] BUG: KASAN: use-after-free in __isofs_iget+0x1c58/0x2010 fs/isofs/inode.c:1555 Read of size 1 at addr ffff88808142c015 by task syz-executor.3/9918 CPU: 0 PID: 9918 Comm: syz-executor.3 Not tainted 4.19.197-syzkaller #0 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:1355 [inline] __isofs_iget+0x1c58/0x2010 fs/isofs/inode.c:1555 wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 isofs_iget fs/isofs/isofs.h:134 [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 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready 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 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 __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:00007feda94f7188 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: 00007fff7a3c8c4f R14: 00007feda94f7300 R15: 0000000000022000 The buggy address belongs to the page: page:ffffea0002050b00 count:0 mapcount:0 mapping:0000000000000000 index:0x1 flags: 0xfff00000000000() raw: 00fff00000000000 ffffea0002055648 ffffea0002052bc8 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808142bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808142bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808142c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88808142c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88808142c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready