Re: [PATCH] xfs: fix NULL pointer dereference in xfs_getbmap()

From: chenxiaosong (A)
Date: Thu Jul 28 2022 - 06:57:54 EST


在 2022/7/27 23:16, Darrick J. Wong 写道:

Heh. Is this worth an fstest? It probably is, since prior to 5.20 this
would have been a UAF bug on top of a NULL deref.

I will try to add regression test to xfstests for this commit when it is merged into mainline.


Nit: it's ILOCK, not i_lock. Otherwise... this looks correct to me --
take the IOLOCK and ILOCK in shared mode before accessing the inode fork
structures.

Do you have any suggestions for Fixes:? I suspect this has been broken
for quite some time.

The "Fixes:" label is: abbf9e8a4507 ("xfs: rewrite getbmap using the xfs_iext_* helpers")


No need to fix the nit, I'll do that when I commit this.
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>

--D