bisecting cause commit starting from 771c577c23bac90597c685971d7297ea00f99d11 building syzkaller on f48c20b8f9b2a6c26629f11cc15e1c9c316572c8 testing commit 771c577c23bac90597c685971d7297ea00f99d11 with gcc (GCC) 8.1.0 kernel signature: 3b33f0dbd601520f2b1674f8fe503e7409737fdf all runs: crashed: WARNING in ext4_set_page_dirty testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.1.0 kernel signature: 19480b6057ee9612c889a0bb0a54b079f8611e52 all runs: crashed: WARNING in ext4_set_page_dirty testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.1.0 kernel signature: ae2e840ad8d75135d9c37176a731d9d06403d919 all runs: crashed: WARNING in dio_complete testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.1.0 kernel signature: d2e5cc2af9cdee6bfb10bf745f23b8931edc6cac run #0: crashed: WARNING in dio_complete run #1: crashed: WARNING in dio_complete run #2: crashed: WARNING in dio_complete run #3: crashed: WARNING in dio_complete run #4: crashed: WARNING in dio_complete run #5: crashed: WARNING in dio_complete run #6: crashed: WARNING in dio_complete run #7: crashed: WARNING in ext4_set_page_dirty run #8: crashed: WARNING in dio_complete run #9: crashed: WARNING in dio_complete testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.1.0 kernel signature: 73d28e41f1e9c218e3110db8d2d3893b6a1de3ee all runs: crashed: WARNING in ext4_set_page_dirty testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.1.0 kernel signature: 1541627589f2e69b2e97595265b0745ffe72a1cd all runs: crashed: WARNING in ext4_set_page_dirty testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.3.0 kernel signature: 5eac917e3131d02cd02cb68d5777b7792c237a9d all runs: crashed: WARNING in ext4_set_page_dirty testing release v4.10 testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0 kernel signature: d822c3e14b81b727eb3870520359fc86973242fe all runs: crashed: WARNING in ext4_set_page_dirty testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 kernel signature: 82b6f65d4907821f8b468dd90978dca057910574 run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #4: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #5: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #6: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #7: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #8: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #9: OK testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 kernel signature: d5c9faaa45d0d84e5e5b62933c4edcc99a4cd4cb run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 kernel signature: 4cd13e39e4ff9be2c4602ce73707003ce413dafe run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 kernel signature: ba308c55215a2af251ac02a0f59763e75b158d56 run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #4: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.5 testing commit b562e44f507e863c6792946e4e1b1449fbbac85d with gcc (GCC) 5.5.0 kernel signature: 79ec4be2fde9d1e5c6ae4fc44b1522468a4566fc run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.4 testing commit afd2ff9b7e1b367172f18ba7f693dfb62bdcb2dc with gcc (GCC) 5.5.0 kernel signature: 913e26f4330754832a47c13153577afe51a14f83 run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.3 testing commit 6a13feb9c82803e2b815eca72fa7a9f5561d7861 with gcc (GCC) 5.5.0 kernel signature: 2fb6d6c93773a0786f2a20106e7e2b1d1c738524 run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.2 testing commit 64291f7db5bd8150a74ad2036f1037e6a0428df2 with gcc (GCC) 5.5.0 kernel signature: c0050948ea81fd430e304beece760f4943f95f77 run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #4: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #5: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #6: OK run #7: OK run #8: OK run #9: OK testing release v4.1 testing commit b953c0d234bc72e8489d3bf51a276c5c4ec85345 with gcc (GCC) 5.5.0 kernel signature: 9717e04fa88b0a0d98698ceeaf0bbedbc31c5c0e run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #4: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #5: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #6: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #7: crashed: kernel BUG at fs/ext4/inode.c:LINE! run #8: OK run #9: OK revisions tested: 17, total time: 3h6m24.325603678s (build: 59m12.446036283s, test: 2h2m35.058364491s) the crash already happened on the oldest tested release commit msg: Linux 4.1 crash: kernel BUG at fs/ext4/inode.c:LINE! bridge0: port 1(bridge_slave_0) entered forwarding state bridge0: port 2(bridge_slave_1) entered forwarding state bridge0: port 1(bridge_slave_0) entered forwarding state ------------[ cut here ]------------ kernel BUG at fs/ext4/inode.c:2345! invalid opcode: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 7541 Comm: syz-executor256 Not tainted 4.1.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88020f9a6a10 ti: ffff880213c94000 task.ti: ffff880213c94000 RIP: 0010:[] [] mpage_prepare_extent_to_map+0x2e0/0x2f0 fs/ext4/inode.c:2345 RSP: 0018:ffff880213c977f8 EFLAGS: 00010246 RAX: 02fffc0000020039 RBX: ffff880213c97828 RCX: 0000000000000001 RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000282 RBP: ffff880213c978d8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000008 R13: 7fffffffffffffff R14: ffffea00084d2a00 R15: ffff880213c97988 FS: 00007fda96422700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fda9635be78 CR3: 00000000b77a6000 CR4: 00000000001407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000000 0000000000000002 ffff8800bb2d3bd0 ffff880213c97858 ffff880213c97838 0000000000000008 0000000000000007 0000000000000000 ffffea00084d2a00 ffffea00084e7940 ffffea00082769c0 ffffea000836f440 Call Trace: [] ext4_writepages+0x52f/0x1300 fs/ext4/inode.c:2500 [] do_writepages+0x1c/0x30 mm/page-writeback.c:2036 [] __filemap_fdatawrite_range+0x51/0x60 mm/filemap.c:284 [] filemap_write_and_wait_range+0x28/0x70 mm/filemap.c:430 [] generic_file_direct_write+0x46/0x170 mm/filemap.c:2346 [] __generic_file_write_iter+0xac/0x1d0 mm/filemap.c:2550 [] ext4_file_write_iter+0x19d/0x4a0 fs/ext4/file.c:170 [] vfs_iter_write+0x62/0xa0 fs/read_write.c:364 [] iter_file_splice_write+0x254/0x3a0 fs/splice.c:1011 [] do_splice_from fs/splice.c:1115 [inline] [] direct_splice_actor+0x31/0x40 fs/splice.c:1281 [] splice_direct_to_actor+0xcc/0x210 fs/splice.c:1234 [] do_splice_direct+0x8a/0xb0 fs/splice.c:1324 [] do_sendfile+0x1ab/0x3a0 fs/read_write.c:1227 [] SYSC_sendfile64 fs/read_write.c:1282 [inline] [] SyS_sendfile64+0x4f/0xb0 fs/read_write.c:1274 [] system_call_fastpath+0x16/0x7a Code: 96 e7 ff e9 9a fe ff ff 0f 1f 00 be 0d 00 00 00 4c 89 f7 e8 c3 91 e7 ff 49 8b 06 f6 c4 20 0f 84 c9 fe ff ff 0f 0b 0f 1f 44 00 00 <0f> 0b 48 8d bd 50 ff ff ff e8 e2 cf e8 ff eb 8b 55 48 89 e5 41 RIP [] mpage_prepare_extent_to_map+0x2e0/0x2f0 fs/ext4/inode.c:2337 RSP ---[ end trace 6c2bc5b545f2e0b3 ]---