While working with fsfuzz encountered the following kernel stack traces. Environment: 2.6.32-rc1 and 2.6.31 (kernel BUG at fs/ext4/extents.c:2833) Architecture: s390 ------------[ cut here ]------------ kernel BUG at fs/ext4/extents.c:2863! illegal operation: 0001 [#1] SMP Modules linked in: cbc md5 aes_s390 aes_generic ecb ecryptfs ext4 jbd2 crc16 autofs4 lockd sunrpc ipv6 loop qeth_l2 qeth qdio vmur ccwgroup dm_round_robin dm_multipath scsi_dh sd_mod scsi_mod multipath dm_snapshot dm_zero dm_mirror dm_region_hash dm_log dm_mod dasd_fba_mod dasd_eckd_mod dasd_mod ext3 jbd CPU: 0 Not tainted 2.6.32-rc2 #1 Process fstest (pid: 5755, task: 0000000024a48038, ksp: 0000000011afbe20) Krnl PSW : 0704000180000000 000003e00200f3f4 (ext4_ext_get_blocks+0x240/0x10cc [ext4]) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 EA:3 Krnl GPRS: 0000000000000000 0000000000000000 0000000000002400 0000000000000000 000000001416c000 000000000c8da000 000000002b539370 0000000000000000 000000002b5390f0 000000002b5390f0 0000000011afba90 000000002b539040 000003e001fe3000 000003e002023198 000003e00200f388 0000000011afb6c8 Krnl Code: 000003e00200f3e8: a71100ff tmll %r1,255 000003e00200f3ec: a7740006 brc 7,3e00200f3f8 000003e00200f3f0: a7f40001 brc 15,3e00200f3f2 >000003e00200f3f4: a7f40000 brc 15,3e00200f3f4 000003e00200f3f8: e3b040100004 lg %r11,16(%r4) 000003e00200f3fe: b90200bb ltgr %r11,%r11 000003e00200f402: a78404ea brc 8,3e00200fdd6 000003e00200f406: 5810b000 l %r1,0(%r11) Call Trace: ([<000003e00200f388>] ext4_ext_get_blocks+0x1d4/0x10cc [ext4]) [<000003e001fed31e>] ext4_get_blocks+0xba/0x3c0 [ext4] [<000003e001fee9d8>] ext4_get_block+0xcc/0x114 [ext4] [<00000000001449ba>] do_mpage_readpage+0x1fa/0x688 [<0000000000144f7a>] mpage_readpages+0xae/0x100 [<00000000000d49f8>] __do_page_cache_readahead+0x160/0x1f4 [<00000000000d4acc>] ra_submit+0x40/0x54 [<00000000000d4f94>] page_cache_sync_readahead+0x40/0x50 [<00000000000cc334>] generic_file_aio_read+0x284/0x6a4 [<000000000010ed34>] do_sync_read+0xd0/0x118 [<000000000010fad0>] vfs_read+0xa8/0x174 [<000000000010fc92>] SyS_read+0x56/0x84 [<0000000000027f5a>] sysc_tracego+0xe/0x14 [<0000004e53f12cc4>] 0x4e53f12cc4 Last Breaking-Event-Address: [<000003e00200f3f0>] ext4_ext_get_blocks+0x23c/0x10cc [ext4] ---[ end trace 7a3a53bbf5dda9be ]--- Related code: 2858 /* 2859 * consistent leaf must not be empty; 2860 * this situation is possible, though, _during_ tree modification; 2861 * this is why assert can't be put in ext4_ext_find_extent() 2862 */ 2863 BUG_ON(path[depth].p_ext == NULL && depth != 0); 2864 eh = path[depth].p_hdr; 2865
Created attachment 23213 [details] fsfuzzer image to recreate the kernel stack trace in tar gzipped format
Created attachment 23214 [details] fsfuzzer ext4 base image
unzip the above file(s) ext4.364.img.tar.gz ext4.base.tar.gz And download the fsfuzzer from URL http://www.risesecurity.org/files/fsfuzzer-0.7.3.tar.gz Untar it cd fsfuzzer-0.7.3 ./configure make cp ext4.364.img to fsfuzzer-0.7.3/cfs cp ext4.base to fsfuzzer-0.7.3/fs and run the file named run_test in dir fsfuzzer-0.7.3 ./run_test ext4 364 Check the dmesg. Thanks!!
Any updates!!
Created attachment 24181 [details] Patch to fix this problem Surbhi Palande has supplied the following patch to address this issue