[Unionfs] Kernel panic

[Fernando A. P. Gomes]

Hi,

I've try'ed unionfs 2.1.7 with kernel 2.6.23.1 and sometimes kernel crashes:

[  122.048224] BUG: unable to handle kernel NULL pointer dereference at 
virtual address 00000020
[  122.065959]  printing eip:
[  122.071566] c01feb2c
[  122.076099] *pde = 00000000
[  122.081880] Oops: 0000 [#1]
[  122.087652] SMP
[  122.091555] CPU:    0
[  122.091556] EIP:    0060:[<c01feb2c>]    Not tainted VLI
[  122.091558] EFLAGS: 00010202   (2.6.23.1etfw #1)
[  122.116754] EIP is at unionfs_flush+0x8e/0x2b2
[  122.125934] eax: 00000010   ebx: 00000010   ecx: dda9e258   edx: 00000000
[  122.139956] esi: dd79e800   edi: db021240   ebp: 00000010   esp: d95adeb0
[  122.153974] ds: 007b   es: 007b   fs: 00d8  gs: 0000  ss: 0068
[  122.166020] Process bash (pid: 2279, ti=d95ad000 task=d94d1540 
task.ti=d95ad000)
[  122.180938] Stack: 00000000 db4ae900 db021240 db4ae900 00000000 00001812 
c015d119 db4ae900
[  122.198632]        db4ae900 00000003 db021240 c015d193 d9561540 00000000 
b7fb17c0 c018479a
[  122.216328]        00000003 00001812 d8f4a8f0 d9963800 d9561540 00000001 
00000000 080f3400
[  122.234022] Call Trace:
[  122.239463]  [<c015d119>] filp_close+0x32/0x54
[  122.248701]  [<c015d193>] sys_close+0x58/0x8d
[  122.257745]  [<c018479a>] load_elf_binary+0x936/0xbc3
[  122.268214]  [<c0160c66>] copy_strings+0x175/0x17f
[  122.278161]  [<c0161a91>] search_binary_handler+0x7f/0x117
[  122.289546]  [<c0161c56>] do_execve+0x12d/0x194
[  122.298956]  [<c010144b>] sys_execve+0x2d/0x74
[  122.308177]  [<c01025ea>] syscall_call+0x7/0xb
[  122.325854]  [<c0530000>] netlbl_secattr_catmap_walk_rng+0x6b/0xed
[  122.347395]  =======================
[  122.363562] Code: 0f 8f ad 00 00 00 31 d2 89 d8 85 ff 0f 94 c2 c1 e8 1f 09 
c2 74 04 0f 0b eb fe 8b 47 70 8b 40 10 8b 04 98 85 c0 0f 84 82 00 00 00 <8b> 
5
[  122.433577] EIP: [<c01feb2c>] unionfs_flush+0x8e/0x2b2 SS:ESP 0068:d95adeb0
[  122.457965] Kernel panic - not syncing: Fatal exception
[  122.478972] Rebooting in 15 seconds..

Can you fix the bug? You want more information? 

Regards,
Fernando Gomes