------------[ 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: 5135 Comm: syz.0.0 Not tainted 6.11.0-rc7-syzkaller-00149-g0babf683783d #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:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 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 dbAllocBits+0x4ea/0x990 fs/jfs/jfs_dmap.c:2193 dbAllocDmap+0x6d/0x150 fs/jfs/jfs_dmap.c:2034 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:2125 __block_write_begin fs/buffer.c:2174 [inline] block_write_begin+0x9b/0x1e0 fs/buffer.c:2235 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:299 generic_perform_write+0x399/0x840 mm/filemap.c:4019 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4147 __kernel_write_iter+0x40d/0x900 fs/read_write.c:523 dump_emit_page fs/coredump.c:893 [inline] dump_user_range+0x4e0/0x950 fs/coredump.c:954 elf_core_dump+0x3de6/0x4720 fs/binfmt_elf.c:2116 do_coredump+0x1b04/0x2a30 fs/coredump.c:767 get_signal+0x13fa/0x1740 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 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_page_fault+0x590/0x8c0 arch/x86/mm/fault.c:1542 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 002b:00000000200000b8 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f320c735f80 RCX: 00007f320c57def9 RDX: 00000000200000c0 RSI: 00000000200000b0 RDI: 0000000008808000 RBP: 00007f320c5f0b76 R08: 0000000020000140 R09: 0000000020000140 R10: 0000000020000100 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f320c735f80 R15: 00007ffcaa9bd5d8 ---[ end trace ]---