From 051c25bbcd298b9f8fbbc478d968aeb9963b663f Mon Sep 17 00:00:00 2001 From: Oleg Drokin Date: Mon, 24 Aug 2015 11:40:08 -0400 Subject: [PATCH] LU-6667 llite: improve ll_getname strncpy_from_user could return negative values on error, so need to take those into account. Since ll_getname is used to get a single component name from userspace to transfer to server as-is, there's no need to allocate 4k buffer as done by __getname. Allocate NAME_MAX+1 buffer instead to ensure we have enough for a null terminated max valid length buffer. Change-Id: I9ce50d33864c7efd6fd019b592199f4fcf75410c Signed-off-by: Oleg Drokin Reviewed-on: http://review.whamcloud.com/15089 Tested-by: Jenkins Tested-by: Maloo Reviewed-by: Andreas Dilger Reviewed-by: James Simmons --- lustre/llite/dir.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/lustre/llite/dir.c b/lustre/llite/dir.c index af02f98..51a42ab 100644 --- a/lustre/llite/dir.c +++ b/lustre/llite/dir.c @@ -1059,29 +1059,33 @@ out: RETURN(rc); } -static char * -ll_getname(const char __user *filename) +/* This function tries to get a single name component, + * to send to the server. No actual path traversal involved, + * so we limit to NAME_MAX */ +static char *ll_getname(const char __user *filename) { int ret = 0, len; - char *tmp = __getname(); + char *tmp; + + OBD_ALLOC(tmp, NAME_MAX + 1); if (!tmp) return ERR_PTR(-ENOMEM); - len = strncpy_from_user(tmp, filename, PATH_MAX); - if (len == 0) + len = strncpy_from_user(tmp, filename, NAME_MAX + 1); + if (len < 0) ret = -ENOENT; - else if (len > PATH_MAX) + else if (len > NAME_MAX) ret = -ENAMETOOLONG; if (ret) { - __putname(tmp); + OBD_FREE(tmp, NAME_MAX + 1); tmp = ERR_PTR(ret); } return tmp; } -#define ll_putname(filename) __putname(filename) +#define ll_putname(filename) OBD_FREE(filename, NAME_MAX + 1); static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { -- 1.8.3.1