From 851ae480e6d09c34b649b738418c30baf8c970d3 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 2 Nov 2016 09:14:16 -0400 Subject: Revert "ima: limit file hash setting by user to fix and log modes" commit f5acb3dcba1ffb7f0b8cbb9dba61500eea5d610b upstream. Userspace applications have been modified to write security xattrs, but they are not context aware. In the case of security.ima, the security xattr can be either a file hash or a file signature. Permitting writing one, but not the other requires the application to be context aware. In addition, userspace applications might write files to a staging area, which might not be in policy, and then change some file metadata (eg. owner) making it in policy. As a result, these files are not labeled properly. This reverts commit c68ed80c97d9720f51ef31fe91560fdd1e121533, which prevents writing file hashes as security.ima xattrs. Requested-by: Patrick Ohly Cc: Dmitry Kasatkin Signed-off-by: Mimi Zohar Cc: Mike Rapoport Signed-off-by: Greg Kroah-Hartman --- security/integrity/ima/ima_appraise.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 8da7c91b725d..c36b98b07d6b 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -383,14 +383,10 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, result = ima_protect_xattr(dentry, xattr_name, xattr_value, xattr_value_len); if (result == 1) { - bool digsig; - if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) return -EINVAL; - digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG); - if (!digsig && (ima_appraise & IMA_APPRAISE_ENFORCE)) - return -EPERM; - ima_reset_appraise_flags(d_backing_inode(dentry), digsig); + ima_reset_appraise_flags(d_backing_inode(dentry), + (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0); result = 0; } return result; -- cgit v1.2.3 From ca100fbc48b4e61fb0e6c3a2c81ad4fc4c185bae Mon Sep 17 00:00:00 2001 From: Sachin Grover Date: Fri, 25 May 2018 14:01:39 +0530 Subject: selinux: KASAN: slab-out-of-bounds in xattr_getsecurity commit efe3de79e0b52ca281ef6691480c8c68c82a4657 upstream. Call trace: [] dump_backtrace+0x0/0x428 [] show_stack+0x28/0x38 [] dump_stack+0xd4/0x124 [] print_address_description+0x68/0x258 [] kasan_report.part.2+0x228/0x2f0 [] kasan_report+0x5c/0x70 [] check_memory_region+0x12c/0x1c0 [] memcpy+0x34/0x68 [] xattr_getsecurity+0xe0/0x160 [] vfs_getxattr+0xc8/0x120 [] getxattr+0x100/0x2c8 [] SyS_fgetxattr+0x64/0xa0 [] el0_svc_naked+0x24/0x28 If user get root access and calls security.selinux setxattr() with an embedded NUL on a file and then if some process performs a getxattr() on that file with a length greater than the actual length of the string, it would result in a panic. To fix this, add the actual length of the string to the security context instead of the length passed by the userspace process. Signed-off-by: Sachin Grover Cc: stable@vger.kernel.org Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- security/selinux/ss/services.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 23dca68ffe25..0a258c0602d1 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1441,7 +1441,7 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len, scontext_len, &context, def_sid); if (rc == -EINVAL && force) { context.str = str; - context.len = scontext_len; + context.len = strlen(str) + 1; str = NULL; } else if (rc) goto out_unlock; -- cgit v1.2.3