kernel/linux.git/security/apparmor, branch v4.19.103

apparmor: don't try to replace stale label in ptrace access check

2020-01-27T13:49:55+00:00

[ Upstream commit 1f8266ff58840d698a1e96d2274189de1bdf7969 ] As a comment above begin_current_label_crit_section() explains, begin_current_label_crit_section() must run in sleepable context because when label_is_stale() is true, aa_replace_current_label() runs, which uses prepare_creds(), which can sleep. Until now, the ptrace access check (which runs with a task lock held) violated this rule. Also add a might_sleep() assertion to begin_current_label_crit_section(), because asserts are less likely to be ignored than comments. Fixes: b2d09ae449ced ("apparmor: move ptrace checks to using labels") Signed-off-by: Jann Horn Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: Fix network performance issue in aa_label_sk_perm

2020-01-27T13:49:54+00:00

[ Upstream commit 5f997580e8b12b9f585e34cc16304925d26ce49e ] The netperf benchmark shows a 5.73% reduction in throughput for small (64 byte) transfers by unconfined tasks. DEFINE_AUDIT_SK() in aa_label_sk_perm() should not be performed unconditionally, rather only when the label is confined. netperf-tcp 56974a6fc^ 56974a6fc Min 64 563.48 ( 0.00%) 531.17 ( -5.73%) Min 128 1056.92 ( 0.00%) 999.44 ( -5.44%) Min 256 1945.95 ( 0.00%) 1867.97 ( -4.01%) Min 1024 6761.40 ( 0.00%) 6364.23 ( -5.87%) Min 2048 11110.53 ( 0.00%) 10606.20 ( -4.54%) Min 3312 13692.67 ( 0.00%) 13158.41 ( -3.90%) Min 4096 14926.29 ( 0.00%) 14457.46 ( -3.14%) Min 8192 18399.34 ( 0.00%) 18091.65 ( -1.67%) Min 16384 21384.13 ( 0.00%) 21158.05 ( -1.06%) Hmean 64 564.96 ( 0.00%) 534.38 ( -5.41%) Hmean 128 1064.42 ( 0.00%) 1010.12 ( -5.10%) Hmean 256 1965.85 ( 0.00%) 1879.16 ( -4.41%) Hmean 1024 6839.77 ( 0.00%) 6478.70 ( -5.28%) Hmean 2048 11154.80 ( 0.00%) 10671.13 ( -4.34%) Hmean 3312 13838.12 ( 0.00%) 13249.01 ( -4.26%) Hmean 4096 15009.99 ( 0.00%) 14561.36 ( -2.99%) Hmean 8192 18975.57 ( 0.00%) 18326.54 ( -3.42%) Hmean 16384 21440.44 ( 0.00%) 21324.59 ( -0.54%) Stddev 64 1.24 ( 0.00%) 2.85 (-130.64%) Stddev 128 4.51 ( 0.00%) 6.53 ( -44.84%) Stddev 256 11.67 ( 0.00%) 8.50 ( 27.16%) Stddev 1024 48.33 ( 0.00%) 75.07 ( -55.34%) Stddev 2048 54.82 ( 0.00%) 65.16 ( -18.86%) Stddev 3312 153.57 ( 0.00%) 56.29 ( 63.35%) Stddev 4096 100.25 ( 0.00%) 88.50 ( 11.72%) Stddev 8192 358.13 ( 0.00%) 169.99 ( 52.54%) Stddev 16384 43.99 ( 0.00%) 141.82 (-222.39%) Signed-off-by: Tony Jones Fixes: 56974a6fcfef ("apparmor: add base infastructure for socket mediation") Signed-off-by: John Johansen Signed-off-by: Sasha Levin

LSM: generalize flag passing to security_capable

2020-01-23T07:21:29+00:00

[ Upstream commit c1a85a00ea66cb6f0bd0f14e47c28c2b0999799f ] This patch provides a general mechanism for passing flags to the security_capable LSM hook. It replaces the specific 'audit' flag that is used to tell security_capable whether it should log an audit message for the given capability check. The reason for generalizing this flag passing is so we can add an additional flag that signifies whether security_capable is being called by a setid syscall (which is needed by the proposed SafeSetID LSM). Signed-off-by: Micah Morton Reviewed-by: Kees Cook Signed-off-by: James Morris Signed-off-by: Sasha Levin

apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock

2020-01-09T09:19:02+00:00

commit 8c62ed27a12c00e3db1c9f04bc0f272bdbb06734 upstream. aa_xattrs_match() is unfortunately calling vfs_getxattr_alloc() from a context protected by an rcu_read_lock. This can not be done as vfs_getxattr_alloc() may sleep regardles of the gfp_t value being passed to it. Fix this by breaking the rcu_read_lock on the policy search when the xattr match feature is requested and restarting the search if a policy changes occur. Fixes: 8e51f9087f40 ("apparmor: Add support for attaching profiles via xattr, presence and value") Reported-by: Jia-Ju Bai Reported-by: Al Viro Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix unsigned len comparison with less than zero

2020-01-04T18:13:08+00:00

[ Upstream commit 00e0590dbaec6f1bcaa36a85467d7e3497ced522 ] The sanity check in macro update_for_len checks to see if len is less than zero, however, len is a size_t so it can never be less than zero, so this sanity check is a no-op. Fix this by making len a ssize_t so the comparison will work and add ulen that is a size_t copy of len so that the min() macro won't throw warnings about comparing different types. Addresses-Coverity: ("Macro compares unsigned to 0") Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels") Signed-off-by: Colin Ian King Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: delete the dentry in aafs_remove() to avoid a leak

2019-12-05T08:21:19+00:00

[ Upstream commit 201218e4d3dfa1346e30997f48725acce3f26d01 ] Although the apparmorfs dentries are always dropped from the dentry cache when the usage count drops to zero, there is no guarantee that this will happen in aafs_remove(), as another thread might still be using it. In this scenario, this means that the dentry will temporarily continue to appear in the results of lookups, even after the call to aafs_remove(). In the case of removal of a profile - it also causes simple_rmdir() on the profile directory to fail, as the directory won't be empty until the usage counts of all child dentries have decreased to zero. This results in the dentry for the profile directory leaking and appearing empty in the file system tree forever. Signed-off-by: Chris Coulson Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: reset pos on failure to unpack for various functions

2019-09-16T06:22:16+00:00

[ Upstream commit 156e42996bd84eccb6acf319f19ce0cb140d00e3 ] Each function that manipulates the aa_ext struct should reset it's "pos" member on failure. This ensures that, on failure, no changes are made to the state of the aa_ext struct. There are paths were elements are optional and the error path is used to indicate the optional element is not present. This means instead of just aborting on error the unpack stream can become unsynchronized on optional elements, if using one of the affected functions. Cc: stable@vger.kernel.org Fixes: 736ec752d95e ("AppArmor: policy routines for loading and unpacking policy") Signed-off-by: Mike Salvatore Signed-off-by: John Johansen Signed-off-by: Sasha Levin

apparmor: enforce nullbyte at end of tag string

2019-06-25T03:35:54+00:00

commit 8404d7a674c49278607d19726e0acc0cae299357 upstream. A packed AppArmor policy contains null-terminated tag strings that are read by unpack_nameX(). However, unpack_nameX() uses string functions on them without ensuring that they are actually null-terminated, potentially leading to out-of-bounds accesses. Make sure that the tag string is null-terminated before passing it to strcmp(). Cc: stable@vger.kernel.org Fixes: 736ec752d95e ("AppArmor: policy routines for loading and unpacking policy") Signed-off-by: Jann Horn Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix PROFILE_MEDIATES for untrusted input

2019-06-25T03:35:54+00:00

commit 23375b13f98c5464c2b4d15f983cc062940f1f4e upstream. While commit 11c236b89d7c2 ("apparmor: add a default null dfa") ensure every profile has a policy.dfa it does not resize the policy.start[] to have entries for every possible start value. Which means PROFILE_MEDIATES is not safe to use on untrusted input. Unforunately commit b9590ad4c4f2 ("apparmor: remove POLICY_MEDIATES_SAFE") did not take into account the start value usage. The input string in profile_query_cb() is user controlled and is not properly checked to be within the limited start[] entries, even worse it can't be as userspace policy is allowed to make us of entries types the kernel does not know about. This mean usespace can currently cause the kernel to access memory up to 240 entries beyond the start array bounds. Cc: stable@vger.kernel.org Fixes: b9590ad4c4f2 ("apparmor: remove POLICY_MEDIATES_SAFE") Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmorfs: fix use-after-free on symlink traversal

2019-05-25T16:23:42+00:00

[ Upstream commit f51dcd0f621caac5380ce90fbbeafc32ce4517ae ] symlink body shouldn't be freed without an RCU delay. Switch apparmorfs to ->destroy_inode() and use of call_rcu(); free both the inode and symlink body in the callback. Signed-off-by: Al Viro Signed-off-by: Sasha Levin