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authorKyle McMartin <kyle@mcmartin.ca>2006-02-07 12:58:47 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-07 16:12:33 -0800
commit1fcbf053e55e961112f237dc690129f0858156f1 (patch)
treec352b63dc2d73e4033d064bb4b5437d76157bfa8 /arch/parisc/hpux
parentb5173119ff10c5538e92a7957a50887ae170b8da (diff)
downloadlinux-1fcbf053e55e961112f237dc690129f0858156f1.tar.gz
[PATCH] sys_hpux: fix strlen_user() race
Userspace can alter the string after the kernel has run strlen_user(). Also: the strlen_user() return value includes the \0, so fix that. Also: handle EFAULT from strlen_user(). It's unlikely anyone is using this code. Very, very unlikely. If I remember correctly, CONFIG_HPUX turns this code on, but one would actually need CONFIG_BINFMT_SOM to load a binary that could cause a problem, and BINFMT_SOM has had an #error in it for quite some time. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/parisc/hpux')
-rw-r--r--arch/parisc/hpux/sys_hpux.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/parisc/hpux/sys_hpux.c b/arch/parisc/hpux/sys_hpux.c
index 29b4d61898f..05273ccced0 100644
--- a/arch/parisc/hpux/sys_hpux.c
+++ b/arch/parisc/hpux/sys_hpux.c
@@ -468,19 +468,23 @@ int hpux_sysfs(int opcode, unsigned long arg1, unsigned long arg2)
if ( opcode == 1 ) { /* GETFSIND */
len = strlen_user((char *)arg1);
printk(KERN_DEBUG "len of arg1 = %d\n", len);
-
- fsname = (char *) kmalloc(len+1, GFP_KERNEL);
+ if (len == 0)
+ return 0;
+ fsname = (char *) kmalloc(len, GFP_KERNEL);
if ( !fsname ) {
printk(KERN_DEBUG "failed to kmalloc fsname\n");
return 0;
}
- if ( copy_from_user(fsname, (char *)arg1, len+1) ) {
+ if ( copy_from_user(fsname, (char *)arg1, len) ) {
printk(KERN_DEBUG "failed to copy_from_user fsname\n");
kfree(fsname);
return 0;
}
+ /* String could be altered by userspace after strlen_user() */
+ fsname[len] = '\0';
+
printk(KERN_DEBUG "that is '%s' as (char *)\n", fsname);
if ( !strcmp(fsname, "hfs") ) {
fstype = 0;