Vasily Tarasov 701e054e0c [PATCH] mounstats NULL pointer dereference ... OpenVZ developers team has encountered the following problem in 2.6.19-rc6 kernel. After some seconds of running script while [[ 1 ]] do find /proc -name mountstats | xargs cat done this Oops appears: BUG: unable to handle kernel NULL pointer dereference at virtual address 00000010 printing eip: c01a6b70 *pde = 00000000 Oops: 0000 [#1] SMP Modules linked in: xt_length ipt_ttl xt_tcpmss ipt_TCPMSS iptable_mangle iptable_filter xt_multiport xt_limit ipt_tos ipt_REJECT ip_tables x_tables parport_pc lp parport sunrpc af_packet thermal processor fan button battery asus_acpi ac ohci_hcd ehci_hcd usbcore i2c_nforce2 i2c_core tg3 floppy pata_amd ide_cd cdrom sata_nv libata CPU: 1 EIP: 0060:[<c01a6b70>] Not tainted VLI EFLAGS: 00010246 (2.6.19-rc6 #2) EIP is at mountstats_open+0x70/0xf0 eax: 00000000 ebx: e6247030 ecx: e62470f8 edx: 00000000 esi: 00000000 edi: c01a6b00 ebp: c33b83c0 esp: f4105eb4 ds: 007b es: 007b ss: 0068 Process cat (pid: 6044, ti=f4105000 task=f4104a70 task.ti=f4105000) Stack: c33b83c0 c04ee940 f46a4a80 c33b83c0 e4df31b4 c01a6b00 f4105000 c0169231 e4df31b4 c33b83c0 c33b83c0 f4105f20 00000003 f4105000 c0169445 f2503cf0 f7f8c4c0 00008000 c33b83c0 00000000 00008000 c0169350 f4105f20 00008000 Call Trace: [<c01a6b00>] mountstats_open+0x0/0xf0 [<c0169231>] __dentry_open+0x181/0x250 [<c0169445>] nameidata_to_filp+0x35/0x50 [<c0169350>] do_filp_open+0x50/0x60 [<c01873d6>] seq_read+0xc6/0x300 [<c0169511>] get_unused_fd+0x31/0xc0 [<c01696d3>] do_sys_open+0x63/0x110 [<c01697a7>] sys_open+0x27/0x30 [<c01030bd>] sysenter_past_esp+0x56/0x79 ======================= Code: 45 74 8b 54 24 20 89 44 24 08 8b 42 f0 31 d2 e8 47 cb f8 ff 85 c0 89 c3 74 51 8d 80 a0 04 00 00 e8 46 06 2c 00 8b 83 48 04 00 00 <8b> 78 10 85 ff 74 03 f0 ff 07 b0 01 86 83 a0 04 00 00 f0 ff 4b EIP: [<c01a6b70>] mountstats_open+0x70/0xf0 SS:ESP 0068:f4105eb4 The problem is that task->nsproxy can be equal NULL for some time during task exit. This patch fixes the BUG. Signed-off-by: Vasily Tarasov <vtaras@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>		2006-11-25 13:28:33 -08:00
..
Makefile	[PATCH] kdump: Access dump file in elf format (/proc/vmcore)	2005-06-25 16:24:53 -07:00
array.c	[PATCH] proc: drop tasklist lock in task_state()	2006-10-02 07:57:24 -07:00
base.c	[PATCH] mounstats NULL pointer dereference	2006-11-25 13:28:33 -08:00
generic.c	[PATCH] mark f_ops const in the inode	2006-03-28 09:16:05 -08:00
inode-alloc.txt	Linux-2.6.12-rc2	2005-04-16 15:20:36 -07:00
inode.c	Mark /proc MS_NOSUID and MS_NOEXEC	2006-07-15 12:20:05 -07:00
internal.h	[PATCH] NOMMU: Implement /proc/pid/maps for NOMMU	2006-09-27 08:26:14 -07:00
kcore.c	[PATCH] Kcore elf note namesz field fix	2006-09-29 09:18:25 -07:00
kmsg.c	[PATCH] Make most file operations structs in fs/ const	2006-03-28 09:16:06 -08:00
mmu.c	[PATCH] fix impossible VmallocChunk	2005-05-17 07:59:10 -07:00
nommu.c	[PATCH] NOMMU: Implement /proc/pid/maps for NOMMU	2006-09-27 08:26:14 -07:00
proc_devtree.c	[PATCH] powerpc: Cope with duplicate node & property names in /proc/device-tree	2006-03-28 16:45:23 +11:00
proc_misc.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	2006-10-05 15:10:12 +01:00
proc_tty.c	Linux-2.6.12-rc2	2005-04-16 15:20:36 -07:00
root.c	[PATCH] proc: give the root directory a task	2006-10-02 07:57:13 -07:00
task_mmu.c	[PATCH] NOMMU: move the fallback arch_vma_name() to a sensible place	2006-09-27 08:26:15 -07:00
task_nommu.c	[PATCH] NOMMU: Implement /proc/pid/maps for NOMMU	2006-09-27 08:26:14 -07:00
vmcore.c	Remove obsolete #include <linux/config.h>	2006-06-30 19:25:36 +02:00