On 9/6/2022 2:03 PM, Paul Moore wrote:
Backport the following upstream commit into Linux v5.19.y:
commit dd9373402280cf4715fdc8fd5070f7d039e43511 Author: Casey Schaufler <casey@schaufler-ca.com> Date: Tue Aug 23 16:46:18 2022 -0700 Smack: Provide read control for io_uring_cmd Limit io_uring "cmd" options to files for which the caller has Smack read access. There may be cases where the cmd option may be closer to a write access than a read, but there is no way to make that determination.Signed-off-by: Paul Moore paul@paul-moore.com
Acked-by: Casey Schaufler casey@schaufler-ca.com
security/smack/smack_lsm.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 6207762dbdb1..b30e20f64471 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -42,6 +42,7 @@ #include <linux/fs_context.h> #include <linux/fs_parser.h> #include <linux/watch_queue.h> +#include <linux/io_uring.h> #include "smack.h" #define TRANS_TRUE "TRUE" @@ -4739,6 +4740,36 @@ static int smack_uring_sqpoll(void) return -EPERM; } +/**
- smack_uring_cmd - check on file operations for io_uring
- @ioucmd: the command in question
- Make a best guess about whether a io_uring "command" should
- be allowed. Use the same logic used for determining if the
- file could be opened for read in the absence of better criteria.
- */
+static int smack_uring_cmd(struct io_uring_cmd *ioucmd) +{
- struct file *file = ioucmd->file;
- struct smk_audit_info ad;
- struct task_smack *tsp;
- struct inode *inode;
- int rc;
- if (!file)
return -EINVAL;- tsp = smack_cred(file->f_cred);
- inode = file_inode(file);
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
- smk_ad_setfield_u_fs_path(&ad, file->f_path);
- rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
- rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
- return rc;
+}
#endif /* CONFIG_IO_URING */ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { @@ -4896,6 +4927,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { #ifdef CONFIG_IO_URING LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds), LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll),
- LSM_HOOK_INIT(uring_cmd, smack_uring_cmd),
#endif };