Messages in this thread | | | From | Parag Warudkar <> | Subject | Re: 2.6.31-rc2: BUG: unable to handle kernel NULL pointer dereference | Date | Sun, 12 Jul 2009 17:30:06 +0000 (UTC) |
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Thomas Meyer <thomas <at> m3y3r.de> writes:
> > [ 6190.368242] Restarting tasks ... done. > [ 6191.252241] BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 > [ 6191.252253] IP: [<ffffffff8134beea>] strchr+0x24/0x45
[ ... ]
> [ 6191.252253] Call Trace: > [ 6191.252253] [<ffffffff812e37d7>] ? selinux_sb_show_options+0x246/0x33c > [ 6191.252253] [<ffffffff811306a2>] ? show_vfsmnt+0xbb/0x133 > [ 6191.252253] [<ffffffff81134785>] ? seq_read+0x293/0x376 > [ 6191.252253] [<ffffffff81117f49>] ? vfs_read+0xb1/0x123 > [ 6191.252253] [<ffffffff811180a3>] ? sys_read+0x55/0x90 > [ 6191.252253] [<ffffffff8102bf2b>] ? system_call_fastpath+0x16/0x1b > [ 6191.252253] Code: d2 ff 48 83 c4 18 c3 48 83 ec 18 48 89 f8 65 48 8b 14 25 28 00 00 00 48 89 54 24 08 31 d2 eb 0b 84 d2 75 04 > 31 c0 eb 0a 48 ff c0 <8a> 10 40 38 f2 75 ee 48 8b 54 24 08 65 48 33 14 25 28 00 00 00 > [ 6191.252253] RIP [<ffffffff8134beea>] strchr+0x24/0x45 > [ 6191.252253] RSP <ffff8801771b9d98> > [ 6191.252253] CR2: 0000000000000040 > [ 6191.258135] ---[ end trace f7a4d612974b9b43 ]---
Hmm. It very likely died in selinux_write_opts. That is the only function that does the strchr in that code path -
static void selinux_write_opts(struct seq_file *m, 1012 struct security_mnt_opts *opts) 1013 { 1014 int i; 1015 char *prefix; 1016 1017 for (i = 0; i < opts->num_mnt_opts; i++) { 1018 char *has_comma; 1019 1020 if (opts->mnt_opts[i]) 1021 has_comma = strchr(opts->mnt_opts[i], ','); ^^^^^^^^^^^^^^^^^^^^^^^^^ And that is a NULL pointer dereference - but we just checked for opts->mnt_opts[i] for not NULL.
Were there other problems before this trace. The Tainted: G seems to suggest that?
Parag
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