From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org,stable@vger.kernel.org,amir73il@gmail.com,phillip@squashfs.org.uk,akpm@linux-foundation.org
Subject: + squashfs-reject-negative-file-sizes-in-squashfs_read_inode.patch added to mm-nonmm-unstable branch
Date: Fri, 26 Sep 2025 18:17:34 -0700 [thread overview]
Message-ID: <20250927011735.18C16C4CEF4@smtp.kernel.org> (raw)
The patch titled
Subject: Squashfs: reject negative file sizes in squashfs_read_inode()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
squashfs-reject-negative-file-sizes-in-squashfs_read_inode.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/squashfs-reject-negative-file-sizes-in-squashfs_read_inode.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Phillip Lougher <phillip@squashfs.org.uk>
Subject: Squashfs: reject negative file sizes in squashfs_read_inode()
Date: Fri, 26 Sep 2025 22:59:35 +0100
Syskaller reports a "WARNING in ovl_copy_up_file" in overlayfs.
This warning is ultimately caused because the underlying Squashfs file
system returns a file with a negative file size.
This commit checks for a negative file size and returns EINVAL.
Link: https://lkml.kernel.org/r/20250926215935.107233-1-phillip@squashfs.org.uk
Fixes: 6545b246a2c8 ("Squashfs: inode operations")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: syzbot+f754e01116421e9754b9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68d580e5.a00a0220.303701.0019.GAE@google.com/
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
fs/squashfs/inode.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
--- a/fs/squashfs/inode.c~squashfs-reject-negative-file-sizes-in-squashfs_read_inode
+++ a/fs/squashfs/inode.c
@@ -145,6 +145,10 @@ int squashfs_read_inode(struct inode *in
goto failed_read;
inode->i_size = le32_to_cpu(sqsh_ino->file_size);
+ if (inode->i_size < 0) {
+ err = -EINVAL;
+ goto failed_read;
+ }
frag = le32_to_cpu(sqsh_ino->fragment);
if (frag != SQUASHFS_INVALID_FRAG) {
/*
@@ -197,6 +201,10 @@ int squashfs_read_inode(struct inode *in
goto failed_read;
inode->i_size = le64_to_cpu(sqsh_ino->file_size);
+ if (inode->i_size < 0) {
+ err = -EINVAL;
+ goto failed_read;
+ }
frag = le32_to_cpu(sqsh_ino->fragment);
if (frag != SQUASHFS_INVALID_FRAG) {
/*
@@ -249,8 +257,12 @@ int squashfs_read_inode(struct inode *in
if (err < 0)
goto failed_read;
- set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
inode->i_size = le16_to_cpu(sqsh_ino->file_size);
+ if (inode->i_size < 0) {
+ err = -EINVAL;
+ goto failed_read;
+ }
+ set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
inode->i_op = &squashfs_dir_inode_ops;
inode->i_fop = &squashfs_dir_ops;
inode->i_mode |= S_IFDIR;
@@ -273,9 +285,13 @@ int squashfs_read_inode(struct inode *in
if (err < 0)
goto failed_read;
+ inode->i_size = le32_to_cpu(sqsh_ino->file_size);
+ if (inode->i_size < 0) {
+ err = -EINVAL;
+ goto failed_read;
+ }
xattr_id = le32_to_cpu(sqsh_ino->xattr);
set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
- inode->i_size = le32_to_cpu(sqsh_ino->file_size);
inode->i_op = &squashfs_dir_inode_ops;
inode->i_fop = &squashfs_dir_ops;
inode->i_mode |= S_IFDIR;
@@ -302,7 +318,7 @@ int squashfs_read_inode(struct inode *in
goto failed_read;
inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);
- if (inode->i_size > PAGE_SIZE) {
+ if (inode->i_size < 0 || inode->i_size > PAGE_SIZE) {
ERROR("Corrupted symlink\n");
return -EINVAL;
}
_
Patches currently in -mm which might be from phillip@squashfs.org.uk are
squashfs-fix-uninit-value-in-squashfs_get_parent.patch
squashfs-add-additional-inode-sanity-checking.patch
squashfs-add-seek_data-seek_hole-support.patch
squashfs-reject-negative-file-sizes-in-squashfs_read_inode.patch
reply other threads:[~2025-09-27 1:17 UTC|newest]
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