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authorAndrey Mirkin <amirkin@openvz.org>2006-12-06 20:31:35 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 08:39:20 -0800
commit822191a2fa1584a29c3224ab328507adcaeac1ab (patch)
tree833b6e7d88fc49bf430826db26f75b4877593a15
parenta1e85378ba50694cf8f27b190c7e16d7c8dad276 (diff)
downloadlinux-822191a2fa1584a29c3224ab328507adcaeac1ab.tar.bz2
[PATCH] skip data conversion in compat_sys_mount when data_page is NULL
OpenVZ Linux kernel team has found a problem with mounting in compat mode. Simple command "mount -t smbfs ..." on Fedora Core 5 distro in 32-bit mode leads to oops: Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: compat_sys_mount+0xd6/0x290 Process mount (pid: 14656, veid=300, threadinfo ffff810034d30000, task ffff810034c86bc0) Call Trace: ia32_sysret+0x0/0xa The problem is that data_page pointer can be NULL, so we should skip data conversion in this case. Signed-off-by: Andrey Mirkin <amirkin@openvz.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/compat.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/compat.c b/fs/compat.c
index 06dad665b88f..7aef5412f49c 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -871,7 +871,7 @@ asmlinkage long compat_sys_mount(char __user * dev_name, char __user * dir_name,
retval = -EINVAL;
- if (type_page) {
+ if (type_page && data_page) {
if (!strcmp((char *)type_page, SMBFS_NAME)) {
do_smb_super_data_conv((void *)data_page);
} else if (!strcmp((char *)type_page, NCPFS_NAME)) {