From mboxrd@z Thu Jan 1 00:00:00 1970 From: zohar@linux.vnet.ibm.com (Mimi Zohar) Date: Wed, 16 Aug 2017 13:30:20 -0400 Subject: [RFC PATCH 4/4] ima: define a new ima_sb_post_remount hook In-Reply-To: <1502904620-20075-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1502904620-20075-1-git-send-email-zohar@linux.vnet.ibm.com> Message-ID: <1502904620-20075-5-git-send-email-zohar@linux.vnet.ibm.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org Compare the previous i_version flag with the remounted i_version flag. Only if there is a change, log change message. Signed-off-by: Mimi Zohar --- include/linux/ima.h | 9 +++++++++ security/integrity/ima/ima_main.c | 22 ++++++++++++++++++++-- security/security.c | 1 + 3 files changed, 30 insertions(+), 2 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index 4475cb01149c..bd98221c00d5 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -25,6 +25,9 @@ extern int ima_post_read_file(struct file *file, void *buf, loff_t size, extern void ima_post_path_mknod(struct dentry *dentry); extern void ima_sb_post_new_mount(const struct vfsmount *newmnt, const struct path *path); +extern void ima_sb_post_remount(const struct super_block *sb, + unsigned long prev_sb_flags, + const struct path *path); #ifdef CONFIG_IMA_KEXEC extern void ima_add_kexec_buffer(struct kimage *image); @@ -70,6 +73,12 @@ static inline void ima_post_path_mknod(struct dentry *dentry) static inline void ima_sb_post_new_mount(const struct vfsmount *newmnt, const struct path *path) { } + +static inline void ima_sb_post_remount(const struct super_block *sb, + unsigned long prev_sb_flags, + const struct path *path) +{ } + #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a0a685189001..1b180f974e8d 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -373,8 +373,10 @@ void ima_sb_post_new_mount(const struct vfsmount *newmnt, sb = newmnt ? newmnt->mnt_sb : path->mnt->mnt_sb; - if ((sb->s_flags & MS_I_VERSION) || (sb->s_flags & MS_RDONLY) || - (sb->s_flags & MS_KERNMOUNT)) + if ((sb->s_flags & MS_KERNMOUNT) || (sb->s_flags & MS_RDONLY)) + return; + + if (newmnt && (sb->s_flags & MS_I_VERSION)) return; for (i = 0; i < ARRAY_SIZE(pseudo_fs); i++) { @@ -394,9 +396,25 @@ void ima_sb_post_new_mount(const struct vfsmount *newmnt, if (newmnt) pr_warn("ima: %s mounted without i_version enabled\n", pathname); + else if (sb->s_flags & MS_I_VERSION) + pr_warn("ima: %s re-mounted with i_version enabled\n", + pathname); + else + pr_warn("ima: %s re-mounted without i_version enabled\n", + pathname); __putname(pathbuf); } +void ima_sb_post_remount(const struct super_block *sb, + unsigned long prev_sb_flags, + const struct path *path) +{ + if ((sb->s_flags & MS_I_VERSION) == (prev_sb_flags & MS_I_VERSION)) + return; /* nothing changed */ + + ima_sb_post_new_mount(NULL, path); +} + /** * ima_read_file - pre-measure/appraise hook decision based on policy * @file: pointer to the file to be measured/appraised/audit diff --git a/security/security.c b/security/security.c index 7981ad9019c9..1e2051a52b9f 100644 --- a/security/security.c +++ b/security/security.c @@ -382,6 +382,7 @@ void security_sb_post_remount(const struct super_block *sb, const struct path *path) { call_void_hook(sb_post_remount, sb, prev_sb_flags, path); + ima_sb_post_remount(sb, prev_sb_flags, path); } int security_sb_kern_mount(struct super_block *sb, int flags, void *data) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html