From: Quentin Casasnovas Date: Tue, 14 Apr 2015 09:25:43 +0000 (+0200) Subject: cdc-acm: prevent infinite loop when parsing CDC headers. X-Git-Tag: omap-for-v4.2/omap1-v2~54^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0d3bba0287d4e284c3ec7d3397e81eec920d5e7e;p=pandora-kernel.git cdc-acm: prevent infinite loop when parsing CDC headers. Phil and I found out a problem with commit: 7e860a6e7aa6 ("cdc-acm: add sanity checks") It added some sanity checks to ignore potential garbage in CDC headers but also introduced a potential infinite loop. This can happen at the first loop iteration (elength = 0 in that case) if the description isn't a DT_CS_INTERFACE or later if 'buffer[0]' is zero. It should also be noted that the wrong length was being added to 'buffer' in case 'buffer[1]' was not a DT_CS_INTERFACE descriptor, since elength was assigned after that check in the loop. A specially crafted USB device could be used to trigger this infinite loop. Fixes: 7e860a6e7aa6 ("cdc-acm: add sanity checks") Signed-off-by: Phil Turnbull Signed-off-by: Quentin Casasnovas CC: Sergei Shtylyov CC: Oliver Neukum CC: Adam Lee CC: Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed