Hello, syzbot found the following issue on: HEAD commit: e32cde8d2bd7 Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17b18307980000 kernel config: https://syzkaller.appspot.com/x/.config?x=286b31f2cf1c36b5 dashboard link: https://syzkaller.appspot.com/bug?extid=de1498ff3a934ac5e8b4 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10718307980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12f3939f980000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-e32cde8d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9c681f5609bc/vmlinux-e32cde8d.xz kernel image: https://storage.googleapis.com/syzbot-assets/00b4d54de1d9/bzImage-e32cde8d.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/14b0b7eafa4c/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+de1498ff3a934ac5e8b4@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: null-ptr-deref in buffer_busy fs/buffer.c:2881 [inline] BUG: KASAN: null-ptr-deref in drop_buffers+0x6f/0x710 fs/buffer.c:2893 Read of size 4 at addr 0000000000000060 by task kswapd0/74 CPU: 0 UID: 0 PID: 74 Comm: kswapd0 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #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: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_report+0xe8/0x550 mm/kasan/report.c:491 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] buffer_busy fs/buffer.c:2881 [inline] drop_buffers+0x6f/0x710 fs/buffer.c:2893 try_to_free_buffers+0x295/0x5f0 fs/buffer.c:2947 shrink_folio_list+0x240c/0x8cc0 mm/vmscan.c:1432 evict_folios+0x549b/0x7b50 mm/vmscan.c:4583 try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4778 shrink_one+0x3b9/0x850 mm/vmscan.c:4816 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5937 kswapd_shrink_node mm/vmscan.c:6765 [inline] balance_pgdat mm/vmscan.c:6957 [inline] kswapd+0x1ca3/0x3700 mm/vmscan.c:7226 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> ================================================================== --- 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 syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. 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