Hello, syzbot found the following issue on: HEAD commit: 14d7c92f8df9 Revert "mm: mmap: allow for the maximum numbe.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16e8c341980000 kernel config: https://syzkaller.appspot.com/x/.config?x=a7c279056fc785df dashboard link: https://syzkaller.appspot.com/bug?extid=d6a7a43c85606b87babd compiler: arm-linux-gnueabi-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: arm Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/8ead8862021c/non_bootable_disk-14d7c92f.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/14a0f94a4c14/vmlinux-14d7c92f.xz kernel image: https://storage.googleapis.com/syzbot-assets/aaa25622f902/zImage-14d7c92f.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d6a7a43c85606b87babd@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7719 at lib/string_helpers.c:1029 __fortify_report+0x6c/0x74 lib/string_helpers.c:1029 strnlen: detected buffer overflow: 17 byte read of buffer size 16 Modules linked in: Kernel panic - not syncing: kernel: panic_on_warn set ... CPU: 0 PID: 7719 Comm: syz-executor.0 Not tainted 6.10.0-rc4-syzkaller #0 Hardware name: ARM-Versatile Express Call trace: [<818d4c98>] (dump_backtrace) from [<818d4d94>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:00000000 r6:82622d44 r5:00000000 r4:81fe1404 [<818d4d7c>] (show_stack) from [<818f23c4>] (__dump_stack lib/dump_stack.c:88 [inline]) [<818d4d7c>] (show_stack) from [<818f23c4>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:114) [<818f2370>] (dump_stack_lvl) from [<818f2404>] (dump_stack+0x18/0x1c lib/dump_stack.c:123) r5:00000000 r4:8285fd18 [<818f23ec>] (dump_stack) from [<818d583c>] (panic+0x120/0x358 kernel/panic.c:347) [<818d571c>] (panic) from [<80243dcc>] (check_panic_on_warn kernel/panic.c:240 [inline]) [<818d571c>] (panic) from [<80243dcc>] (print_tainted+0x0/0xa0 kernel/panic.c:235) r3:8260c5c4 r2:00000001 r1:81fca074 r0:81fd1cc4 r7:8080f8d0 [<80243d58>] (check_panic_on_warn) from [<80243fc0>] (__warn+0x7c/0x180 kernel/panic.c:693) [<80243f44>] (__warn) from [<802442ac>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:726) r8:00000009 r7:8202ef04 r6:eab31db4 r5:84670c00 r4:00000000 [<802440c8>] (warn_slowpath_fmt) from [<8080f8d0>] (__fortify_report+0x6c/0x74 lib/string_helpers.c:1029) r10:8271c088 r9:00000003 r8:eab31ec3 r7:8408b000 r6:20000080 r5:837f3478 r4:83f1c800 [<8080f864>] (__fortify_report) from [<818df088>] (__fortify_panic+0x10/0x14 lib/string_helpers.c:1036) [<818df078>] (__fortify_panic) from [<8062b018>] (strnlen include/linux/fortify-string.h:235 [inline]) [<818df078>] (__fortify_panic) from [<8062b018>] (sized_strscpy include/linux/fortify-string.h:309 [inline]) [<818df078>] (__fortify_panic) from [<8062b018>] (ext4_ioctl_getlabel fs/ext4/ioctl.c:1154 [inline]) [<818df078>] (__fortify_panic) from [<8062b018>] (ext4_fileattr_get+0x0/0x78 fs/ext4/ioctl.c:1609) [<80628f04>] (__ext4_ioctl) from [<8062b714>] (ext4_ioctl+0x10/0x14 fs/ext4/ioctl.c:1626) r10:84670c00 r9:00000003 r8:8747d3c0 r7:20000080 r6:8747d3c1 r5:00000000 r4:81009431 [<8062b704>] (ext4_ioctl) from [<8051a9ac>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8062b704>] (ext4_ioctl) from [<8051a9ac>] (do_vfs_ioctl fs/ioctl.c:861 [inline]) [<8062b704>] (ext4_ioctl) from [<8051a9ac>] (__do_sys_ioctl fs/ioctl.c:905 [inline]) [<8062b704>] (ext4_ioctl) from [<8051a9ac>] (sys_ioctl+0x134/0xda4 fs/ioctl.c:893) [<8051a878>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xeab31fa8 to 0xeab31ff0) 1fa0: 00000000 00000000 00000003 81009431 20000080 00000000 1fc0: 00000000 00000000 001542c8 00000036 7ea87336 7ea87337 003d0f00 76b280fc 1fe0: 76b27f08 76b27ef8 00016f30 000516d0 r10:00000036 r9:84670c00 r8:8020029c r7:00000036 r6:001542c8 r5:00000000 r4:00000000 Rebooting in 86400 seconds.. --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup