bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67 building syzkaller on 5abc3f1ab298244473b613c289f1536e366fcf04 testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.1.0 kernel signature: 79c4fd562bd998024d754d65714ba0fb1b5e8d33248562bad6ec7ebc99c363a2 run #0: crashed: KASAN: use-after-free Read in diFree run #1: crashed: KASAN: use-after-free Read in diFree run #2: crashed: KASAN: use-after-free Read in diFree run #3: crashed: KASAN: use-after-free Read in diFree run #4: crashed: KASAN: use-after-free Read in diFree run #5: crashed: general protection fault in diFree run #6: crashed: KASAN: use-after-free Read in diFree run #7: crashed: general protection fault in diFree run #8: crashed: general protection fault in diFree run #9: crashed: general protection fault in diFree testing current HEAD 2b79150141611d3c6e1b55d4e70f49602482f0b8 testing commit 2b79150141611d3c6e1b55d4e70f49602482f0b8 with gcc (GCC) 8.1.0 kernel signature: 7524aeb720a925000c6856684721b2a210f30db6d8b9c24b1242db217524114b run #0: crashed: general protection fault in diFree run #1: crashed: KASAN: use-after-free Read in diFree run #2: crashed: KASAN: use-after-free Read in diFree run #3: crashed: KASAN: use-after-free Read in diFree run #4: crashed: KASAN: use-after-free Read in diFree run #5: crashed: KASAN: use-after-free Read in diFree run #6: crashed: KASAN: use-after-free Read in diFree run #7: crashed: general protection fault in diFree run #8: crashed: KASAN: use-after-free Read in diFree run #9: crashed: KASAN: use-after-free Read in diFree revisions tested: 2, total time: 22m52.515564353s (build: 16m18.681430469s, test: 6m1.058429259s) the crash still happens on HEAD commit msg: Linux 4.14.203 crash: KASAN: use-after-free Read in diFree ERROR: (device loop2): xtSearch: XT_GETPAGE: xtree page corrupt ERROR: (device loop3): xtSearch: XT_GETPAGE: xtree page corrupt ERROR: (device loop5): xtSearch: XT_GETPAGE: xtree page corrupt ERROR: (device loop0): xtSearch: XT_GETPAGE: xtree page corrupt ================================================================== BUG: KASAN: use-after-free in diFree+0x153c/0x32a0 fs/jfs/jfs_imap.c:892 Read of size 4 at addr ffff88808e6d0ac4 by task syz-executor.2/8536 ERROR: (device loop4): xtSearch: XT_GETPAGE: xtree page corrupt CPU: 1 PID: 8536 Comm: syz-executor.2 Not tainted 4.14.203-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1f1 lib/dump_stack.c:58 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.7+0x11a/0x2d4 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 diFree+0x153c/0x32a0 fs/jfs/jfs_imap.c:892 ERROR: (device loop1): xtSearch: XT_GETPAGE: xtree page corrupt jfs_evict_inode+0xd1/0x110 fs/jfs/inode.c:164 evict+0x29c/0x590 fs/inode.c:555 iput_final fs/inode.c:1524 [inline] iput+0x3ac/0x810 fs/inode.c:1551 diFreeSpecial+0x5d/0x80 fs/jfs/jfs_imap.c:569 jfs_umount+0xce/0x300 fs/jfs/jfs_umount.c:78 jfs_fill_super+0x61d/0xaf0 fs/jfs/super.c:633 mount_bdev+0x26f/0x330 fs/super.c:1134 jfs_do_mount+0x10/0x20 fs/jfs/super.c:703 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4607ea RSP: 002b:00007f591db70a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f591db70b20 RCX: 00000000004607ea RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f591db70ae0 RBP: 00007f591db70ae0 R08: 00007f591db70b20 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000200 R15: 000000002006d200 Allocated by task 8536: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:551 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:536 kmem_cache_alloc_trace+0x152/0x3f0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] diMount+0x4d/0x680 fs/jfs/jfs_imap.c:118 jfs_mount+0x27f/0x340 fs/jfs/jfs_mount.c:190 jfs_fill_super+0x524/0xaf0 fs/jfs/super.c:589 mount_bdev+0x26f/0x330 fs/super.c:1134 jfs_do_mount+0x10/0x20 fs/jfs/super.c:703 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 8536: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xab/0x190 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 diUnmount+0xdb/0x120 fs/jfs/jfs_imap.c:210 jfs_umount+0xc6/0x300 fs/jfs/jfs_umount.c:76 jfs_fill_super+0x61d/0xaf0 fs/jfs/super.c:633 mount_bdev+0x26f/0x330 fs/super.c:1134 jfs_do_mount+0x10/0x20 fs/jfs/super.c:703 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff88808e6d0ac0 which belongs to the cache kmalloc-32768 of size 32768 The buggy address is located 4 bytes inside of 32768-byte region [ffff88808e6d0ac0, ffff88808e6d8ac0) The buggy address belongs to the page: page:ffffea000239b400 count:1 mapcount:0 mapping:ffff88808e6d0ac0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffff88808e6d0ac0 0000000000000000 0000000100000001 raw: ffffea0002490420 ffffea0002398020 ffff8880b6402380 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808e6d0980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808e6d0a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88808e6d0a80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff88808e6d0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808e6d0b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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