On 2015/6/2 12:44, Greg KH wrote: > On Tue, Jun 02, 2015 at 12:05:32PM +0800, Junling Zheng wrote: >> On 2015/6/2 9:21, Greg KH wrote: >>> On Mon, Jun 01, 2015 at 09:28:00AM +0000, Junling Zheng wrote: >>>> Hi, Greg: >>>> >>>> We found that after v3.10.73, recvmsg might return -EFAULT while -EINVAL >>>> was expected. >>> >>> That means I messed up and applied something I shouldn't have, right? >>> >>> Can you use 'git bisect' to find the problem patch? That's probably >>> easier here, and then I can either revert it, or fix up a broken >>> backport. >>> >> >> So, the problem commit is 281c9c36 (net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour), which fixes db31c55a6fb2 >> and brings the get_compat_msghdr() in line with copy_msghdr_from_user(). > > Ok, but that patch itself isn't the issue, as it's "correct". Something I don't think so. The commit 281c9c36 is indeed the issue. Its upstream commit 91edd09 has no problem in mainline, however it's not appropriate or complete for 3.10-stable. It changes the return value of get_compat_msghdr(), however, the outer caller still returns -EFAULT unconditionally, which goes against the intention of author. So, I don't think 281c9c36 is an complete patch for 3.10-stable. We should also fix it to return a correct value according to get_compat_msghdr() rather than returning -EFAULT unconditionally :) Cheers, Junling > else must be wrong here, did we backport db31c55a6fb2 incorrectly to > 3.10-stable? What is really causing this to be so different that your > proposed patch needs to be applied to solve it? > > thanks, > > greg k-h > > . > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html