Messages in this thread Patch in this message | | | From | Eric Sandeen <> | Subject | Re: [PATCH] xfs: check the return value of krealloc() in xfs_uuid_mount | Date | Wed, 25 Nov 2020 09:55:27 -0600 |
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On 11/25/20 12:50 AM, Qinglang Miao wrote: > krealloc() may fail to expand the memory space.
Even with __GFP_NOFAIL?
* ``GFP_KERNEL | __GFP_NOFAIL`` - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders.
> Add sanity checks to it, > and WARN() if that really happened.
As aside, there is no WARN added in this patch for a memory failure.
> Fixes: 771915c4f688 ("xfs: remove kmem_realloc()") > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> > --- > fs/xfs/xfs_mount.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c > index 150ee5cb8..c07f48c32 100644 > --- a/fs/xfs/xfs_mount.c > +++ b/fs/xfs/xfs_mount.c > @@ -80,9 +80,13 @@ xfs_uuid_mount( > } > > if (hole < 0) { > - xfs_uuid_table = krealloc(xfs_uuid_table, > + uuid_t *if_xfs_uuid_table; > + if_xfs_uuid_table = krealloc(xfs_uuid_table, > (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table), > GFP_KERNEL | __GFP_NOFAIL); > + if (!if_xfs_uuid_table) > + goto out_duplicate;
And this would emit "Filesystem has duplicate UUID" which is not correct.
But anyway, the __GFP_NOFAIL in the call makes this all moot AFAICT.
-Eric
> + xfs_uuid_table = if_xfs_uuid_table; > hole = xfs_uuid_table_size++; > } > xfs_uuid_table[hole] = *uuid; >
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