I just updated my kernel from 2.6.31.6 (error not occured in old kernel and it ran 34 days (reboot due kernel update)) one day ago. I was changing owner (by chown) and got Segmentation fault. Partition is ext3. If you need additional information, just ask me. Error in log:

Jan  9 23:01:45 server kernel: [72565.047369] ------------[ cut here ]------------
Jan  9 23:01:45 server kernel: [72565.047608] kernel BUG at fs/quota/dquot.c:1398!
Jan  9 23:01:45 server kernel: [72565.047842] invalid opcode: 0000 [#1] SMP
Jan  9 23:01:45 server kernel: [72565.048078] last sysfs file: /sys/devices/pci0000:00/0000:00:01.0/0000:01:0d.0/0000:02:05.0/host0/uevent
Jan  9 23:01:45 server kernel: [72565.048502] CPU 1
Jan  9 23:01:45 server kernel: [72565.048502] Modules linked in:
Jan  9 23:01:45 server kernel: [72565.048502] Pid: 3429, comm: chown Not tainted 2.6.31.11_pepe18 #1 PRIMERGY Econel 230R
Jan  9 23:01:45 server kernel: [72565.048502] RIP: 0010:[<ffffffff810d36ba>]  [<ffffffff810d36ba>] dquot_transfer+0x12b/0x498
Jan  9 23:01:45 server kernel: [72565.048502] RSP: 0018:ffff880067b4bd78  EFLAGS: 00010246
Jan  9 23:01:45 server kernel: [72565.048502] RAX: 0000000000000000 RBX: ffff88007f6bd008 RCX: 0000000000000003
Jan  9 23:01:45 server kernel: [72565.048502] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88007f6bd008
Jan  9 23:01:45 server kernel: [72565.048502] RBP: ffff880067b4be08 R08: 00000000000004a6 R09: 00000000000000fa
Jan  9 23:01:45 server kernel: [72565.048502] R10: 00000000000003e8 R11: ffff880067b4bda8 R12: ffff88007f6bcf58
Jan  9 23:01:45 server kernel: [72565.048502] R13: 0000000000000001 R14: 0000000000001000 R15: ffff88007f707780
Jan  9 23:01:45 server kernel: [72565.048502] FS:  00007fd3eb3496f0(0000) GS:ffff880001617000(0000) knlGS:00000000f74786c0
Jan  9 23:01:45 server kernel: [72565.048502] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Jan  9 23:01:45 server kernel: [72565.048502] CR2: 00007fd3eaea8610 CR3: 000000007ebf9000 CR4: 00000000000006a0
Jan  9 23:01:45 server kernel: [72565.048502] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Jan  9 23:01:45 server kernel: [72565.048502] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Jan  9 23:01:45 server kernel: [72565.048502] Process chown (pid: 3429, threadinfo ffff880067b4a000, task ffff88007d00ced0)
Jan  9 23:01:45 server kernel: [72565.048502] Stack:
Jan  9 23:01:45 server kernel: [72565.048502]  0000000000000292 ffff88007f6bcf58 ffff88007f667200 0000000000000000
Jan  9 23:01:45 server kernel: [72565.048502] <0> 0000000000000000 0000000000000000 ffff88007d014800 00000000ffffffff
Jan  9 23:01:45 server kernel: [72565.048502] <0> ffff880067b4be08 ffffffff810d3b34 ffff88007f660000 0000000000000000
Jan  9 23:01:45 server kernel: [72565.048502] Call Trace:
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff810d3b34>] ? dquot_initialize+0x10d/0x11e
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff810d0b0c>] vfs_dq_transfer+0x6b/0x88
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff810e7eda>] ext3_setattr+0xa0/0x1b9
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff810a6828>] notify_change+0x17e/0x2ca
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff81092513>] chown_common+0x69/0x80
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff81092716>] sys_fchownat+0x5a/0x7c
Jan  9 23:01:45 server kernel: [72565.048502]  [<ffffffff8100b9eb>] system_call_fastpath+0x16/0x1b
Jan  9 23:01:45 server kernel: [72565.048502] Code: 4c 89 e7 e8 e4 32 fc ff 48 89 df 49 89 c6 e8 80 8c 28 00 49 8b 84 24 00 01 00 00 48 8b 40 40 48 8b 80 88 00 00 00 48 85 c0 75 04 <0f> 0b eb fe 4c 89 e7 ff d0 4c 8b 38 41 fe 84 24 b0 00 00 00 4b
Jan  9 23:01:45 server kernel: [72565.048502] RIP  [<ffffffff810d36ba>] dquot_transfer+0x12b/0x498
Jan  9 23:01:45 server kernel: [72565.048502]  RSP <ffff880067b4bd78>
Jan  9 23:01:45 server kernel: [72565.058354] ---[ end trace eac2f8a868f633e2 ]---