During early boot, the filesystem is read-only and any changes to xattrs are not allowed. This fails in case of ext4 because changing xattr starts an ext4 transaction which fails with the following warning.
WARNING: fs/ext4/ext4_jbd2.c:75 at ext4_journal_check_start+0x63/0xa0 [ext4], CPU#1: systemd-sysroot/561 CPU: 1 UID: 0 PID: 561 Comm: systemd-sysroot Not tainted 6.19.12-1-default #1 PREEMPT(voluntary) openSUSE Tumbleweed c2dfc3c9d9f6f1233251c5d4410574fe82a348ee Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:ext4_journal_check_start+0x63/0xa0 [ext4] Call Trace: __ext4_journal_start_sb+0x3e/0x180 [ext4 6d025f3bc52c89a957b89a89d211fadf5e9434e1] ext4_xattr_set+0x104/0x150 [ext4 6d025f3bc52c89a957b89a89d211fadf5e9434e1] __vfs_setxattr+0x9a/0xd0 __vfs_setxattr_noperm+0x76/0x1f0 ima_appraise_measurement+0x23e/0xe40 ima_d_path+0x5a/0xd0 process_measurement+0xb29/0xc40 ? copy_from_kernel_nofault+0x21/0xe0 ? fscrypt_file_open+0xc0/0xe0 ? ext4_file_open+0x60/0x490 [ext4 6d025f3bc52c89a957b89a89d211fadf5e9434e1] ? bpf_prog_31efb7c56239148b_restrict_filesystems+0xab/0x126 ? __bpf_prog_exit+0x23/0xd0 ? __bpf_tramp_exit+0xd/0x50 ? bpf_trampoline_6442530367+0x9f/0xea ima_file_check+0x57/0x80 security_file_post_open+0x50/0xf0 path_openat+0x493/0x1650 do_filp_open+0xc7/0x170 Detect the state of the file early and return the error. Signed-off-by: Goldwyn Rodrigues <[email protected]> --- security/integrity/ima/ima_appraise.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 870dde67707b..6a4dda46114c 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -90,6 +90,11 @@ static int ima_fix_xattr(struct dentry *dentry, int rc, offset; u8 algo = iint->ima_hash->algo; + if (IS_RDONLY(d_inode(dentry))) + return -EROFS; + if (IS_IMMUTABLE(d_inode(dentry))) + return -EPERM; + if (algo <= HASH_ALGO_SHA1) { offset = 1; iint->ima_hash->xattr.sha1.type = IMA_XATTR_DIGEST; -- 2.53.0
