In the unlikely setup where there's only one resource group in the gfs2 filesystem, gfs2_rgrpd_get_next() returns a NULL rgd that is not dealt with properly, causing a kernel NULL ptr dereference. This patch fixes this issue.
This bug was reported in rhel6: https://bugzilla.redhat.com/show_bug.cgi?id=838638 Signed-off-by: Abhi Das <a...@redhat.com> diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index e53d0a1..fb70792 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1276,6 +1276,7 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested) /* fall through */ case GLR_TRYFAILED: rgd = gfs2_rgrpd_get_next(rgd); + rgd = rgd ? : begin; /* if NULL, wrap */ if (rgd != begin) /* If we didn't wrap */ break;
