From: Ian Kent In function validate_dev_ioctl() we check that the string we've been sent is a valid path. The function that does this check assumes the string is NULL terminated but our NULL termination check isn't done until after this call. This patch changes the order of the check. Signed-off-by: Ian Kent Cc: Jeff Moyer Signed-off-by: Andrew Morton --- fs/autofs4/dev-ioctl.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff -puN fs/autofs4/dev-ioctl.c~autofs4-fix-string-validation-check-order fs/autofs4/dev-ioctl.c --- a/fs/autofs4/dev-ioctl.c~autofs4-fix-string-validation-check-order +++ a/fs/autofs4/dev-ioctl.c @@ -124,7 +124,7 @@ static inline void free_dev_ioctl(struct /* * Check sanity of parameter control fields and if a path is present - * check that it has a "/" and is terminated. + * check that it is terminated and contains at least one "/". */ static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) { @@ -138,15 +138,16 @@ static int validate_dev_ioctl(int cmd, s } if (param->size > sizeof(*param)) { - err = check_name(param->path); + err = invalid_str(param->path, + (void *) ((size_t) param + param->size)); if (err) { - AUTOFS_WARN("invalid path supplied for cmd(0x%08x)", - cmd); + AUTOFS_WARN( + "path string terminator missing for cmd(0x%08x)", + cmd); goto out; } - err = invalid_str(param->path, - (void *) ((size_t) param + param->size)); + err = check_name(param->path); if (err) { AUTOFS_WARN("invalid path supplied for cmd(0x%08x)", cmd); _