diff options
| author | Kyle McMartin <kyle@mcmartin.ca> | 2006-02-07 12:58:47 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-07 16:12:33 -0800 |
| commit | 1fcbf053e55e961112f237dc690129f0858156f1 (patch) | |
| tree | c352b63dc2d73e4033d064bb4b5437d76157bfa8 /arch/parisc | |
| parent | b5173119ff10c5538e92a7957a50887ae170b8da (diff) | |
[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')
| -rw-r--r-- | arch/parisc/hpux/sys_hpux.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/arch/parisc/hpux/sys_hpux.c b/arch/parisc/hpux/sys_hpux.c index 29b4d61898f2..05273ccced0e 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; |