From: Mimi Zohar Date: Tue, 28 Jul 2026 00:39:41 +0000 (-0400) Subject: ima: Instantiate file_truncate and path_truncate hooks X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b80bed5c871a80151351342c065579405ce77145;p=thirdparty%2Fkernel%2Flinux.git ima: Instantiate file_truncate and path_truncate hooks Instantiate the file_truncate and path_truncate LSM hooks to reset the action cache flags (IMA_DONE_MASK) as soon as truncation is requested, so the file, based on policy, is re-collected, re-measured, re-audited, and re-appraised on next access. Tested-by: Frederick Lawler Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar --- diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5cea53fc36df..ff52becc3031 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -687,6 +687,43 @@ static int ima_file_check(struct file *file, int mask) MAY_APPEND), FILE_CHECK, 0, false); } +/* + * ima_reset_action_flags - invalidate action flags after a content change + * @inode: inode of the file whose content is about to be truncated + * + * Clear IMA_DONE_MASK so the file is re-collected, re-measured, + * re-audited, and re-appraised on next access. + */ +static void ima_reset_action_flags(struct inode *inode) +{ + struct ima_iint_cache *iint; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + + iint = ima_iint_find(inode); + if (!iint) + return; + + mutex_lock(&iint->mutex); + iint->flags &= ~IMA_DONE_MASK; + iint->measured_pcrs = 0; + mutex_unlock(&iint->mutex); + return; +} + +static int ima_path_truncate(const struct path *path) +{ + ima_reset_action_flags(path->dentry->d_inode); + return 0; +} + +static int ima_file_truncate(struct file *file) +{ + ima_reset_action_flags(file_inode(file)); + return 0; +} + static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf, size_t buf_size) { @@ -1300,11 +1337,13 @@ static struct security_hook_list ima_hooks[] __ro_after_init = { LSM_HOOK_INIT(file_release, ima_file_free), LSM_HOOK_INIT(mmap_file, ima_file_mmap), LSM_HOOK_INIT(file_mprotect, ima_file_mprotect), + LSM_HOOK_INIT(file_truncate, ima_file_truncate), LSM_HOOK_INIT(kernel_load_data, ima_load_data), LSM_HOOK_INIT(kernel_post_load_data, ima_post_load_data), LSM_HOOK_INIT(kernel_read_file, ima_read_file), LSM_HOOK_INIT(kernel_post_read_file, ima_post_read_file), LSM_HOOK_INIT(path_post_mknod, ima_post_path_mknod), + LSM_HOOK_INIT(path_truncate, ima_path_truncate), #ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS LSM_HOOK_INIT(key_post_create_or_update, ima_post_key_create_or_update), #endif