fs/jfs/xattr.c in the Linux kernel before 2.6.35.2 does not properly handle a certain legacy format for storage of extended attributes, which might allow local users by bypass intended xattr namespace restrictions via an "os2." substring at the beginning of a name.

Last updated 24 July 2024

Description of problem: This problem was originally tracked down by Brad Spengler.

When calling wireless ioctls, if a driver does not correctly validate/shrink iwp->length, the resulting copytouser can leak up to 64K of kernel heap contents.

It seems that this is triggerable[1] in 2.6.32 at least on ath5k, but I was not able to track down how. The twisty maze of ioctl handlers stumped me. :) Other drivers I checked did not appear to have any problems, but the potential remains. I'm not sure if this patch is the right approach; it was fixed differently[2] in grsecurity.

[1] http://forums.grsecurity.net/viewtopic.php?f=3&t=2290&start=0 [2] http://grsecurity.net/~spender/wireless-infoleak-fix2.patch

Discussion: http://lkml.org/lkml/2010/8/27/413