Re: general protection fault: 0000 [#1] SMP
From: Jesper Juhl
Date: Sat Nov 20 2010 - 17:45:23 EST
On Sat, 20 Nov 2010, Jesper Juhl wrote:
> On Sat, 20 Nov 2010, Justin Mattock wrote:
>
> > Ive seen this before, but could not reproduce for a bisect.. basically
> > what I remember doing
> > was building webkit(let sit and compile) passed out, woke up at 5AM
> > closed the lid on the machine,few hrs later
> > woke up, went for a run, came back opened the lid and this:
> >
> > [43925.668053] general protection fault: 0000 [#1] SMP
> > [43925.668059] last sysfs file: /sys/devices/platform/applesmc.768/light
> > [43925.668061] CPU 0
> > [43925.668063] Modules linked in: firewire_sbp2 radeon sco bnep ttm
> > drm_kms_helper drm ipt_LOG iptable_nat nf_nat xt_state
> > nf_conntrack_ftp nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4
> > iptable_filter ip_tables x_tables ath9k ath9k_common video ath9k_hw
> > sky2 firewire_ohci battery ac ath evdev joydev button firewire_core
> > i2c_i801 kvm_intel aes_x86_64 lzo zlib ipcomp xfrm_ipcomp crypto_null
> > sha256_generic cbc des_generic cast5 blowfish serpent camellia
> > twofish_generic twofish_x86_64 twofish_common ctr ah4 esp4 authenc
> > uhci_hcd ehci_hcd hci_uart rfcomm btusb hidp l2cap bluetooth coretemp
> > acpi_cpufreq processor mperf appletouch applesmc uvcvideo
> > [43925.668120]
> > [43925.668123] Pid: 27262, comm: make Not tainted
> > 2.6.37-rc2-00037-g7957f0a-dirty #6 Mac-F42187C8/MacBookPro2,2
> > [43925.668126] RIP: 0010:[<ffffffff811bf10a>] [<ffffffff811bf10a>]
> > inode_has_perm+0x53/0x6a
> > [43925.668135] RSP: 0018:ffff88003c5a5bc8 EFLAGS: 00010282
> > [43925.668137] RAX: ffff88003826a208 RBX: ffff88000008ed80 RCX: ffff88003c5a5c68
> > [43925.668140] RDX: 0000000000000002 RSI: ffff88000008ed80 RDI: ffff88002feacc00
> > [43925.668142] RBP: ffff88003c5a5c58 R08: ffff88003c5a5c68 R09: 00000000000000d5
> > [43925.668145] R10: 050366048b660e04 R11: 0000000000000000 R12: 0000000000000024
> > [43925.668147] R13: 00000000ffffffd8 R14: 0000000000000000 R15: 0000000000000000
> > [43925.668150] FS: 00007f4f786b3700(0000) GS:ffff88003ee00000(0000)
> > knlGS:0000000000000000
> > [43925.668153] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [43925.668155] CR2: 00007f4f78637000 CR3: 00000000383ac000 CR4: 00000000000006e0
> > [43925.668158] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > [43925.668161] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> > [43925.668163] Process make (pid: 27262, threadinfo ffff88003c5a4000,
> > task ffff880001afb410)
> > [43925.668165] Stack:
> > [43925.668167] ffff880038a98060 0000000000000000 ffff88003c5a5c48
> > ffffffff81182b7c
> > [43925.668172] ffff88003cab2688 ffff880024da9990 ffff88003caa18d8
> > ffff880038a98060
> > [43925.668177] ffff880024da98b0 ffffea0000a54940 ffff88003c5a5c78
> > ffff88003d402500
> > [43925.668182] Call Trace:
> > [43925.668189] [<ffffffff81182b7c>] ? jbd2_journal_stop+0x21e/0x230
> > [43925.668193] [<ffffffff811be4bb>] ? selinux_cred_free+0xb/0x27
> > [43925.668196] [<ffffffff811be441>] ? selinux_file_alloc_security+0x4a/0xb9
> > [43925.668201] [<ffffffff810f4226>] ? check_object+0x13b/0x1eb
> > [43925.668205] [<ffffffff811bf853>] selinux_inode_permission+0xd2/0xd4
> > [43925.668211] [<ffffffff811bbf9c>] security_inode_permission+0x1c/0x1e
> > [43925.668215] [<ffffffff81101ab2>] inode_permission+0x87/0x93
> > [43925.668218] [<ffffffff81102e86>] may_open+0x9e/0x11e
> > [43925.668221] [<ffffffff8110373e>] do_last+0x542/0x6fa
> > [43925.668225] [<ffffffff811056ec>] do_filp_open+0x1f3/0x646
> > [43925.668228] [<ffffffff810f4226>] ? check_object+0x13b/0x1eb
> > [43925.668232] [<ffffffff81103958>] ? getname+0x2c/0x1be
> > [43925.668236] [<ffffffff8110eca8>] ? alloc_fd+0x111/0x123
> > [43925.668240] [<ffffffff810f7a84>] do_sys_open+0x5b/0xf8
> > [43925.668243] [<ffffffff810f7b4a>] sys_open+0x1b/0x1d
> > [43925.668248] [<ffffffff8102b542>] system_call_fastpath+0x16/0x1b
> > [43925.668250] Code: 02 00 00 44 8b 48 04 48 85 c9 75 1f 4c 8d 85 70
> > ff ff ff b9 22 00 00 00 4c 89 c7 44 89 d8 f3 ab c6 85 70 ff ff ff 01
> > 48 89 75 90 <41> 0f b7 42 20 89 d1 41 8b 72 1c 89 c2 44 89 cf e8 99 e7
> > ff ff
> > [43925.668288] RIP [<ffffffff811bf10a>] inode_has_perm+0x53/0x6a
> > [43925.668291] RSP <ffff88003c5a5bc8>
> > [43925.668295] ---[ end trace 75bdddc506717838 ]---
> > [43934.866252] general protection fault: 0000 [#2] SMP
> > [43934.866257] last sysfs file: /sys/devices/platform/applesmc.768/light
> > [43934.866260] CPU 0
> > [43934.866261] Modules linked in: firewire_sbp2 radeon sco bnep ttm
> > drm_kms_helper drm ipt_LOG iptable_nat nf_nat xt_state
> > nf_conntrack_ftp nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4
> > iptable_filter ip_tables x_tables ath9k ath9k_common video ath9k_hw
> > sky2 firewire_ohci battery ac ath evdev joydev button firewire_core
> > i2c_i801 kvm_intel aes_x86_64 lzo zlib ipcomp xfrm_ipcomp crypto_null
> > sha256_generic cbc des_generic cast5 blowfish serpent camellia
> > twofish_generic twofish_x86_64 twofish_common ctr ah4 esp4 authenc
> > uhci_hcd ehci_hcd hci_uart rfcomm btusb hidp l2cap bluetooth coretemp
> > acpi_cpufreq processor mperf appletouch applesmc uvcvideo
> > [43934.866318]
> > [43934.866321] Pid: 27283, comm: make Tainted: G D
> > 2.6.37-rc2-00037-g7957f0a-dirty #6 Mac-F42187C8/MacBookPro2,2
> > [43934.866324] RIP: 0010:[<ffffffff811bf10a>] [<ffffffff811bf10a>]
> > inode_has_perm+0x53/0x6a
> > [43934.866334] RSP: 0018:ffff88003c5a5bc8 EFLAGS: 00010282
> > [43934.866336] RAX: ffff88003807a958 RBX: ffff88000008ed80 RCX: ffff88003c5a5c68
> > [43934.866339] RDX: 0000000000000002 RSI: ffff88000008ed80 RDI: ffff880034b01700
> > [43934.866341] RBP: ffff88003c5a5c58 R08: ffff88003c5a5c68 R09: 00000000000000d5
> > [43934.866343] R10: 050366048b660e04 R11: 0000000000000000 R12: 0000000000000024
> > [43934.866346] R13: 00000000ffffffd8 R14: 0000000000000000 R15: 0000000000000000
> > [43934.866349] FS: 00007fdf0a661700(0000) GS:ffff88003ee00000(0000)
> > knlGS:0000000000000000
> > [43934.866352] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [43934.866354] CR2: 00007fdf0a5e5000 CR3: 0000000029800000 CR4: 00000000000006e0
> > [43934.866357] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > [43934.866359] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> > [43934.866362] Process make (pid: 27283, threadinfo ffff88003c5a4000,
> > task ffff880001afb410)
> > [43934.866364] Stack:
> > [43934.866366] ffff88002f398a50 ffff880024da9990 000000003c5a5c78
> > ffffffff81810be8
> > [43934.866371] 0020000000000001 0000000000000001 0000000000001000
> > ffff880037bc0a00
> > [43934.866375] 0000000000001000 ffffea0000a54940 ffff88003c5a5d18
> > ffff88003d402500
> > [43934.866380] Call Trace:
> > [43934.866385] [<ffffffff811be4bb>] ? selinux_cred_free+0xb/0x27
> > [43934.866389] [<ffffffff811be441>] ? selinux_file_alloc_security+0x4a/0xb9
> > [43934.866395] [<ffffffff810f4226>] ? check_object+0x13b/0x1eb
> > [43934.866398] [<ffffffff811bf853>] selinux_inode_permission+0xd2/0xd4
> > [43934.866404] [<ffffffff811bbf9c>] security_inode_permission+0x1c/0x1e
> > [43934.866409] [<ffffffff81101ab2>] inode_permission+0x87/0x93
> > [43934.866412] [<ffffffff81102e86>] may_open+0x9e/0x11e
> > [43934.866415] [<ffffffff8110373e>] do_last+0x542/0x6fa
> > [43934.866419] [<ffffffff811056ec>] do_filp_open+0x1f3/0x646
> > [43934.866422] [<ffffffff810f4226>] ? check_object+0x13b/0x1eb
> > [43934.866426] [<ffffffff81103958>] ? getname+0x2c/0x1be
> > [43934.866430] [<ffffffff8110eca8>] ? alloc_fd+0x111/0x123
> > [43934.866433] [<ffffffff810f7a84>] do_sys_open+0x5b/0xf8
> > [43934.866437] [<ffffffff810f7b4a>] sys_open+0x1b/0x1d
> > [43934.866441] [<ffffffff8102b542>] system_call_fastpath+0x16/0x1b
> > [43934.866443] Code: 02 00 00 44 8b 48 04 48 85 c9 75 1f 4c 8d 85 70
> > ff ff ff b9 22 00 00 00 4c 89 c7 44 89 d8 f3 ab c6 85 70 ff ff ff 01
> > 48 89 75 90 <41> 0f b7 42 20 89 d1 41 8b 72 1c 89 c2 44 89 cf e8 99 e7
> > ff ff
> > [43934.866481] RIP [<ffffffff811bf10a>] inode_has_perm+0x53/0x6a
> > [43934.866484] RSP <ffff88003c5a5bc8>
> > [43934.866488] ---[ end trace 75bdddc506717839 ]---
> >
> [...]
>
> Hmm, ok, I have no idea about the root cause of this problem, but I did
> notice one thing about selinux_cred_free() that's different than most
> other freeing functions in the kernel. It does not accept a NULL value.
> Most other freeing functions will just return if passed NULL, but
> selinux_cred_free() will crash.
> I wonder if it would make sense to add a NULL 'short circuit' to that
> function? If so, please pick up the patch below.
>
>
> Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
> ---
> hooks.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 65fa8bf..d088532 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -3193,11 +3193,11 @@ static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
> */
> static void selinux_cred_free(struct cred *cred)
> {
> - struct task_security_struct *tsec = cred->security;
> -
> + if (!cred)
> + return;
> BUG_ON((unsigned long) cred->security < PAGE_SIZE);
> cred->security = (void *) 0x7UL;
> - kfree(tsec);
> + kfree(cred->security);
> }
>
> /*
>
Arrgh, sent the wrong (early version) patch. This is what it should have
been:
Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
hooks.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 65fa8bf..00f28dc 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3193,9 +3193,12 @@ static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
*/
static void selinux_cred_free(struct cred *cred)
{
- struct task_security_struct *tsec = cred->security;
+ struct task_security_struct *tsec;
+ if (!cred)
+ return;
BUG_ON((unsigned long) cred->security < PAGE_SIZE);
+ tsec = cred->security;
cred->security = (void *) 0x7UL;
kfree(tsec);
}
--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
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