bisecting fixing commit since 46cf053efec6a3a5f343fead837777efe8252a46 building syzkaller on be5c2c81971442d623dd1b265dabf4644ceeb35b testing commit 46cf053efec6a3a5f343fead837777efe8252a46 with gcc (GCC) 8.1.0 kernel signature: 2d3518ab5f60ef1ff80144e7b7ddea6678e54fd05f5685459be731658a31410b run #0: crashed: WARNING in ext4_set_page_dirty run #1: crashed: WARNING in ext4_set_page_dirty run #2: crashed: WARNING in ext4_set_page_dirty run #3: crashed: WARNING in ext4_set_page_dirty run #4: crashed: WARNING in ext4_set_page_dirty run #5: crashed: WARNING in ext4_set_page_dirty run #6: crashed: WARNING in ext4_set_page_dirty run #7: crashed: WARNING in ext4_set_page_dirty run #8: OK run #9: OK testing current HEAD 1b5044021070efa3259f3e9548dc35d1eb6aa844 testing commit 1b5044021070efa3259f3e9548dc35d1eb6aa844 with gcc (GCC) 8.1.0 kernel signature: 01b12f5fbbd4b4f041a3be1d296393d99be73109475bc10186310b1d65fa9fd8 run #0: crashed: WARNING in ext4_set_page_dirty run #1: crashed: WARNING in ext4_set_page_dirty run #2: crashed: WARNING in ext4_set_page_dirty run #3: crashed: WARNING in ext4_set_page_dirty run #4: crashed: WARNING in ext4_set_page_dirty run #5: crashed: WARNING in ext4_set_page_dirty run #6: crashed: WARNING in ext4_set_page_dirty run #7: crashed: WARNING in ext4_set_page_dirty run #8: OK run #9: OK revisions tested: 2, total time: 36m0.862835149s (build: 12m51.230302523s, test: 22m30.385180716s) the crash still happens on HEAD commit msg: Merge tag 'dma-mapping-5.8-3' of git://git.infradead.org/users/hch/dma-mapping crash: WARNING in ext4_set_page_dirty ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2701 at fs/ext4/inode.c:3601 PagePrivate include/linux/page-flags.h:357 [inline] WARNING: CPU: 1 PID: 2701 at fs/ext4/inode.c:3601 ext4_set_page_dirty+0x200/0x2d0 fs/ext4/inode.c:3601 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2701 Comm: kworker/1:6 Not tainted 5.8.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events xdp_umem_release_deferred Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x134/0x187 lib/dump_stack.c:118 panic+0x22a/0x4e3 kernel/panic.c:231 __warn.cold.12+0x25/0x27 kernel/panic.c:600 report_bug+0x1b5/0x260 lib/bug.c:198 exc_invalid_op+0x1be/0x370 arch/x86/kernel/traps.c:235 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:563 RIP: 0010:ext4_set_page_dirty+0x200/0x2d0 fs/ext4/inode.c:3601 Code: c6 e0 61 db 87 48 8d 50 ff a8 01 48 0f 45 da 48 89 df e8 b3 99 a8 ff 0f 0b 48 c7 c6 c0 62 db 87 48 89 df e8 a2 99 a8 ff 0f 0b <0f> 0b eb b3 80 3c 02 00 0f 85 ae 00 00 00 48 8b 43 08 48 c7 c6 e0 RSP: 0018:ffffc90008d27c40 EFLAGS: 00010246 RAX: 00fffe0000000015 RBX: ffffea0001d47a40 RCX: ffffffff81eb3cb4 RDX: 1ffffd40003a8f48 RSI: 0000000000000008 RDI: ffffea0001d47a40 RBP: ffffc90008d27c58 R08: fffff940003a8f49 R09: fffff940003a8f49 R10: ffffea0001d47a47 R11: fffff940003a8f48 R12: ffffea0001d47a40 R13: ffffea0001d47a48 R14: ffffffff81eb3b20 R15: 0000000000000003 set_page_dirty+0x20e/0x550 mm/page-writeback.c:2582 set_page_dirty_lock+0x65/0x90 mm/page-writeback.c:2607 unpin_user_pages_dirty_lock+0x11c/0x240 mm/gup.c:312 xdp_umem_unpin_pages.isra.3+0x32/0xa0 net/xdp/xdp_umem.c:184 xdp_umem_release net/xdp/xdp_umem.c:217 [inline] xdp_umem_release_deferred+0x157/0x1d0 net/xdp/xdp_umem.c:227 process_one_work+0x893/0x1680 kernel/workqueue.c:2269 worker_thread+0x85/0xb60 kernel/workqueue.c:2415 kthread+0x383/0x460 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Kernel Offset: disabled