Author: hailfinger Date: Sun Mar 13 18:36:49 2016 New Revision: 1953 URL: http://flashrom.org/trac/flashrom/changeset/1953
Log: Fix fscanf format string security bug in layout.c
An internal security audit of the flashrom project by Carl-Daniel Hailfinger found a buffer overflow bug present in all flashrom versions since the year 2005. This bug was independently found and reported to flashrom.org by Cosmin Gorgovan a few days ago.
A buffer on the stack and a buffer on the heap are affected by the overflow caused by an incorrect fscanf format string. The buffer overflow can only be triggered if the optional layout feature is used and if the user manually specifies a specially crafted layout file on the command line. Command line parsing and flash image handling do not trigger the buggy code path. Most usage of flashrom does not involve layout files.
The fix in this commit (changed fscanf format string) can be applied to layout.c of all past flashrom versions.
Signed-off-by: Carl-Daniel Hailfinger c-d.hailfinger.devel.2006@gmx.net Acked-by: Stefan Tauner stefan.tauner@alumni.tuwien.ac.at
Modified: trunk/layout.c
Modified: trunk/layout.c ============================================================================== --- trunk/layout.c Sun Mar 13 17:24:09 2016 (r1952) +++ trunk/layout.c Sun Mar 13 18:36:49 2016 (r1953) @@ -68,7 +68,7 @@ (void)fclose(romlayout); return 1; } - if (2 != fscanf(romlayout, "%s %s\n", tempstr, rom_entries[num_rom_entries].name)) + if (2 != fscanf(romlayout, "%255s %255s\n", tempstr, rom_entries[num_rom_entries].name)) continue; #if 0 // fscanf does not like arbitrary comments like that :( later