Description of problem: list_dir_proc uses a buffer allocated on the stack for the file name. This is sized as EXT2_NAME_LEN and the length of the string is checked: char name[EXT2_NAME_LEN]; ... thislen = ((dirent->name_len & 0xFF) < EXT2_NAME_LEN) ? (dirent->name_len & 0xFF) : EXT2_NAME_LEN; Finally, we copy the string and set the name[thislen] to '\0'. In the case that thislen == EXT2_NAME_LEN, the '\0' char is stored outside the bounds of the name array. Version-Release number of selected component (if applicable): e2fsprogs-1.35-12.4.EL4 How reproducible: 100% Steps to Reproduce: This isn't easy to reproduce as the stack layout (on i386 anyway) means that an overflow of 1 byte does not overwrite any other datastructures. 1. Create a filename with length equal to EXT2_NAME_LEN 2. Open the filesystem with debugfs running under gdb 3. Set a breakpoint on list_dir_proc 3. List directory contents 4. Continue until the long filename appears in *dirent 5. Store a known character in the byte following the end of name[] 6. Step through the routine until after the "name[thislen] = '\0';" Actual results: The byte after the end of name[] is overwritten. Expected results: The assignment stays within the array bounds.
Created attachment 148062 [details] Patch correcting array usage in ls_dir_proc
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
upstream commits for cid-11, cid-12, cid-13 at http://thunk.org/hg/e2fsprogs/?rev/4c321a4ecbd6
Applying a DEV_ACK for Eric Sandeen <sandeen>. This bug was found by coverity and has a patch available.
In cvs as of e2fsprogs-1.35-12.7.el4
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2007-0758.html