| Message ID | 1471999065-8788-1-git-send-email-bo.li.liu@oracle.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Tue, Aug 23, 2016 at 05:37:45PM -0700, Liu Bo wrote: > When btree node (level = 1) has nritems which equals to zero, > we can end up with panic due to insert_ptr()'s > > BUG_ON(slot > nritems); > > where slot is 1 and nritems is 0, as copy_for_split() calls > insert_ptr(.., path->slots[1] + 1, ...); > > A invalid value results in the whole mess, this adds the check > for btree's node nritems so that we stop reading block when > when something is wrong. > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> > --- > v2: - remove unnecessary "noinline" > - fix to do the proper check as BTRFS_NODEPTRS_PER_BLOCK(root) is inclusive and nr is unsigned. > > fs/btrfs/disk-io.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 90f57fa..682816d 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -633,6 +633,19 @@ static noinline int check_leaf(struct btrfs_root *root, > return 0; > } > > +static int check_node(struct btrfs_root *root, struct extent_buffer *node) > +{ > + unsigned long nr = btrfs_header_nritems(node); > + > + if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root)) { > + btrfs_crit(root->fs_info, > + "corrupt node: block %llu root %llu nritems %lu\n", I'll drop the newline. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 90f57fa..682816d 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -633,6 +633,19 @@ static noinline int check_leaf(struct btrfs_root *root, return 0; } +static int check_node(struct btrfs_root *root, struct extent_buffer *node) +{ + unsigned long nr = btrfs_header_nritems(node); + + if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root)) { + btrfs_crit(root->fs_info, + "corrupt node: block %llu root %llu nritems %lu\n", + node->start, root->objectid, nr); + return -EIO; + } + return 0; +} + static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, u64 phy_offset, struct page *page, u64 start, u64 end, int mirror) @@ -703,6 +716,9 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, ret = -EIO; } + if (found_level > 0 && check_node(root, eb)) + ret = -EIO; + if (!ret) set_extent_buffer_uptodate(eb); err:
When btree node (level = 1) has nritems which equals to zero, we can end up with panic due to insert_ptr()'s BUG_ON(slot > nritems); where slot is 1 and nritems is 0, as copy_for_split() calls insert_ptr(.., path->slots[1] + 1, ...); A invalid value results in the whole mess, this adds the check for btree's node nritems so that we stop reading block when when something is wrong. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- v2: - remove unnecessary "noinline" - fix to do the proper check as BTRFS_NODEPTRS_PER_BLOCK(root) is inclusive and nr is unsigned. fs/btrfs/disk-io.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)