Re: [PATCH] bcachefs: Fix unit-value within btree_bounce_alloc()

[Kent Overstreet]

On Sat, Apr 26, 2025 at 12:53:49AM +0800, I Hsin Cheng wrote:
> On Wed, Apr 23, 2025 at 12:45:20PM -0400, Kent Overstreet wrote:
> > On Thu, Apr 24, 2025 at 12:37:18AM +0800, I Hsin Cheng wrote:
> > > Use "kvzalloc()" instead of "kvmalloc()" in btree_bounce_alloc() to
> > > prevent uninit-value issue.
> > > 
> > > Reported-by: syzbot+549710bad9c798e25b15@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Closes: https://syzkaller.appspot.com/bug?extid=549710bad9c798e25b15
> > > Fixes: cb6fc943b650 ("bcachefs: kill kvpmalloc()")
> > > Signed-off-by: I Hsin Cheng <richard120310@xxxxxxxxx>
> > > ---
> > > syzbot reported an uninit-value issue. [1]
> > > 
> > > Though the uninit value was detected in the context of crc32_body(), the
> > > memory was actually allocated in "btree_bounce_alloc()". Use
> > > "kvzalloc()" to allocate the memory can solve the issue, and I've tested
> > > against syzbot. [2]
> > > 
> > > If there're any further tests needed to be performed, please let me
> > > know. I'll be more than happy to assist you with that, thanks !
> > 
> > See Documentation/filesystems/bcachefs/SubmittingPatches.
> >
> 
> Sure ! Thanks for the info.
> 
> > And this isn't the correct fix - the correct fix is already in Linus's
> > tree.
> 
> Ahh ok, may I ask for the commit hash or title so I can learn from it ?

9c3a2c9b471a bcachefs: Disable asm memcpys when kmsan enabled