From: Keith Mannthey <[email protected]> According to the standard, listxattr(2) should return -1 and errno should be set to ERANGE if the size of the list buffer is too small to hold the result. However ll_listxattr() will return a value bigger than the size of buffer in some cases.
Let's assume listxattr(2) returns SIZE when it is called with a large enough list buffer. If it's called again with a list buffer whose size is smaller than SIZE but bigger than (SIZE - 12), then listxattr(2) will return SIZE too. This patch fixes the problem. Original patch by Li Xi <[email protected]> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3403 Lustre-change: http://review.whamcloud.com/6463 Signed-off-by: Keith Mannthey <[email protected]> Reviewed-by: Li Xi <[email protected]> Reviewed-by: Dmitry Eremin <[email protected]> Reviewed-by: Oleg Drokin <[email protected]> Signed-off-by: Peng Tao <[email protected]> Signed-off-by: Andreas Dilger <[email protected]> --- drivers/staging/lustre/lustre/llite/xattr.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/staging/lustre/lustre/llite/xattr.c b/drivers/staging/lustre/lustre/llite/xattr.c index 0a11902..2e3ff6d 100644 --- a/drivers/staging/lustre/lustre/llite/xattr.c +++ b/drivers/staging/lustre/lustre/llite/xattr.c @@ -564,7 +564,12 @@ ssize_t ll_listxattr(struct dentry *dentry, char *buffer, size_t size) const size_t name_len = sizeof("lov") - 1; const size_t total_len = prefix_len + name_len + 1; - if (buffer && (rc + total_len) <= size) { + if (((rc + total_len) > size) && (buffer != NULL)) { + ptlrpc_req_finished(request); + return -ERANGE; + } + + if (buffer != NULL) { buffer += rc; memcpy(buffer, XATTR_LUSTRE_PREFIX, prefix_len); memcpy(buffer + prefix_len, "lov", name_len); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
