From: Artem Savkov Date: Tue, 13 Sep 2016 21:40:35 +0000 (+1000) Subject: Make __xfs_xattr_put_listen preperly report errors. X-Git-Url: http://git.efficios.com/?p=deliverable%2Flinux.git;a=commitdiff_plain;h=0312017cbbb5f46dbf4932f65df0c2c66f9c8f27 Make __xfs_xattr_put_listen preperly report errors. commit 791cc43b36eb1f88166c8505900cad1b43c7fe1a upstream. Commit 2a6fba6 "xfs: only return -errno or success from attr ->put_listent" changes the returnvalue of __xfs_xattr_put_listen to 0 in case when there is insufficient space in the buffer assuming that setting context->count to -1 would be enough, but all of the ->put_listent callers only check seen_enough. This results in a failed assertion: XFS: Assertion failed: context->count >= 0, file: fs/xfs/xfs_xattr.c, line: 175 in insufficient buffer size case. This is only reproducible with at least 2 xattrs and only when the buffer gets depleted before the last one. Furthermore if buffersize is such that it is enough to hold the last xattr's name, but not enough to hold the sum of preceeding xattr names listxattr won't fail with ERANGE, but will suceed returning last xattr's name without the first character. The first character end's up overwriting data stored at (context->alist - 1). Signed-off-by: Artem Savkov Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner Cc: Eric Sandeen Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c index ea62245fee26..62900938f26d 100644 --- a/fs/xfs/xfs_xattr.c +++ b/fs/xfs/xfs_xattr.c @@ -147,6 +147,7 @@ __xfs_xattr_put_listent( arraytop = context->count + prefix_len + namelen + 1; if (arraytop > context->firstu) { context->count = -1; /* insufficient space */ + context->seen_enough = 1; return 0; } offset = (char *)context->alist + context->count;