From: Ben Hutchings Date: Sun, 8 Oct 2017 13:48:44 +0000 (+0100) Subject: ext3: preserve i_mode if ext2_set_acl() fails X-Git-Tag: v3.2.94~24 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4a79ebbdd0231a4afcd758314b3852501694e44f;p=thirdparty%2Fkernel%2Fstable.git ext3: preserve i_mode if ext2_set_acl() fails Based on Ernesto A. Fernández's fix for ext2 (commit fe26569eb919), from which the following description is taken: > When changing a file's acl mask, ext2_set_acl() will first set the group > bits of i_mode to the value of the mask, and only then set the actual > extended attribute representing the new acl. > > If the second part fails (due to lack of space, for example) and the file > had no acl attribute to begin with, the system will from now on assume > that the mask permission bits are actual group permission bits, potentially > granting access to the wrong users. > > Prevent this by only changing the inode mode after the acl has been set. Cc: Ernesto A. Fernández Cc: Jan Kara Signed-off-by: Ben Hutchings --- diff --git a/fs/ext3/acl.c b/fs/ext3/acl.c index 0a6db91b556e9..c84a8f6ce4c3f 100644 --- a/fs/ext3/acl.c +++ b/fs/ext3/acl.c @@ -231,15 +231,22 @@ ext3_set_acl(handle_t *handle, struct inode *inode, int type, struct posix_acl *acl) { int error; + int update_mode = 0; + umode_t mode = inode->i_mode; if (type == ACL_TYPE_ACCESS && acl) { - error = posix_acl_update_mode(inode, &inode->i_mode, &acl); + error = posix_acl_update_mode(inode, &mode, &acl); if (error) return error; + update_mode = 1; + } + error = __ext3_set_acl(handle, inode, type, acl); + if (!error && update_mode) { + inode->i_mode = mode; inode->i_ctime = CURRENT_TIME_SEC; ext3_mark_inode_dirty(handle, inode); } - return __ext3_set_acl(handle, inode, type, acl); + return error; } /*