Re: [PATCH] squashfs: fix inode lookup sanity checks
From: Phillip Lougher
Date: Fri Feb 26 2021 - 15:14:36 EST
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On 26/02/2021 09:29 Sean Nyekjaer <sean@xxxxxxxxxx> wrote:
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When mouting a squashfs image created without inode compression it
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fails with: "unable to read inode lookup table"
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It turns out that the BLOCK_OFFSET is missing when checking
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the SQUASHFS_METADATA_SIZE agaist the actual size.
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Fixes: eabac19e40c0 ("squashfs: add more sanity checks in inode lookup")
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CC: stable@xxxxxxxxxxxxxxx
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Signed-off-by: Sean Nyekjaer <sean@xxxxxxxxxx>
Acked-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
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---
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fs/squashfs/export.c | 8 ++++++--
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fs/squashfs/squashfs_fs.h | 1 +
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2 files changed, 7 insertions(+), 2 deletions(-)
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diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c
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index eb02072d28dd..723763746238 100644
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--- a/fs/squashfs/export.c
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+++ b/fs/squashfs/export.c
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@@ -152,14 +152,18 @@ __le64 *squashfs_read_inode_lookup_table(struct super_block *sb,
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start = le64_to_cpu(table[n]);
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end = le64_to_cpu(table[n + 1]);
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- if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
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+ if (start >= end
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+ || (end - start) >
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+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
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kfree(table);
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return ERR_PTR(-EINVAL);
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}
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}
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start = le64_to_cpu(table[indexes - 1]);
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- if (start >= lookup_table_start || (lookup_table_start - start) > SQUASHFS_METADATA_SIZE) {
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+ if (start >= lookup_table_start ||
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+ (lookup_table_start - start) >
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+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
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kfree(table);
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return ERR_PTR(-EINVAL);
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}
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diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
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index 8d64edb80ebf..b3fdc8212c5f 100644
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--- a/fs/squashfs/squashfs_fs.h
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+++ b/fs/squashfs/squashfs_fs.h
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@@ -17,6 +17,7 @@
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/* size of metadata (inode and directory) blocks */
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#define SQUASHFS_METADATA_SIZE 8192
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+#define SQUASHFS_BLOCK_OFFSET 2
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/* default size of block device I/O */
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#ifdef CONFIG_SQUASHFS_4K_DEVBLK_SIZE
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--
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2.29.2