------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2902:18 index -3 is out of range for type 's8[1365]' (aka 'signed char[1365]') CPU: 0 UID: 0 PID: 5331 Comm: syz.0.0 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429 dbAdjTree+0x377/0x520 fs/jfs/jfs_dmap.c:2902 dbAdjCtl+0x32d/0x9c0 fs/jfs/jfs_dmap.c:2533 dbAllocDmap+0xcb/0x150 fs/jfs/jfs_dmap.c:2044 dbAlloc+0x509/0xca0 fs/jfs/jfs_dmap.c:816 extBalloc fs/jfs/jfs_extent.c:326 [inline] extAlloc+0x4f8/0x1010 fs/jfs/jfs_extent.c:122 jfs_get_block+0x41b/0xe60 fs/jfs/inode.c:248 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2121 block_write_begin+0x8f/0x120 fs/buffer.c:2231 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:299 generic_perform_write+0x344/0x6d0 mm/filemap.c:4054 generic_file_write_iter+0xae/0x310 mm/filemap.c:4181 __kernel_write_iter+0x42a/0x940 fs/read_write.c:616 dump_emit_page fs/coredump.c:884 [inline] dump_user_range+0x4e0/0x950 fs/coredump.c:945 elf_core_dump+0x3e85/0x4770 fs/binfmt_elf.c:2121 do_coredump+0x2162/0x2ec0 fs/coredump.c:758 get_signal+0x13fc/0x1740 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x280 kernel/entry/common.c:231 exc_general_protection+0x410/0x5d0 arch/x86/kernel/traps.c:693 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7fc23e97e721 Code: 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 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:00000000200004c0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fc23eb35f80 RCX: 00007fc23e97e719 RDX: 0000000000000000 RSI: 00000000200004c0 RDI: 0000000080040000 RBP: 00007fc23e9f132e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc23eb35f80 R15: 00007ffdb42775a8