Messages in this thread | | | Date | Mon, 28 Mar 2022 12:40:59 +0900 | Subject | Re: [PATCH] fs: xfs: add NULL pointer check | From | Damien Le Moal <> |
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On 3/28/22 12:26, cgel.zte@gmail.com wrote: > From: Lv Ruyi <lv.ruyi@zte.com.cn> > > kmem_zalloc() is a memory allocation function which can return NULL when > some internal memory errors happen. It is safer to check NULL pointer. > > Reported-by: Zeal Robot <zealci@zte.com.cn> > Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn> > --- > fs/xfs/libxfs/xfs_attr_leaf.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c > index 014daa8c542d..e6694f49f563 100644 > --- a/fs/xfs/libxfs/xfs_attr_leaf.c > +++ b/fs/xfs/libxfs/xfs_attr_leaf.c > @@ -1571,6 +1571,8 @@ xfs_attr3_leaf_compact( > trace_xfs_attr_leaf_compact(args); > > tmpbuffer = kmem_alloc(args->geo->blksize, 0);
See kmem_alloc() code: this function cannot fail (it retries the allocation until success). So checking for NULL pointer does not make sense.
> + if (!tmpbuffer) > + return; > memcpy(tmpbuffer, bp->b_addr, args->geo->blksize); > memset(bp->b_addr, 0, args->geo->blksize); > leaf_src = (xfs_attr_leafblock_t *)tmpbuffer; > @@ -2290,6 +2292,8 @@ xfs_attr3_leaf_unbalance( > struct xfs_attr3_icleaf_hdr tmphdr; > > tmp_leaf = kmem_zalloc(state->args->geo->blksize, 0); > + if (!tmp_leaf) > + return; > > /* > * Copy the header into the temp leaf so that all the stuff
-- Damien Le Moal Western Digital Research
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