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authorYannick GICQUEL <yannick.gicquel@iot.bzh>2015-10-19 15:57:07 +0200
committerGerrit Code Review <gerrit@172.30.200.200>2015-11-06 15:23:36 +0000
commitede19ea0c47fb23f3fc779833d1e57cf76f3371e (patch)
tree47d6fae2283c54def1871aaf2a73828ac68b1b34 /meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/0052-smack-fix-possible-use-after-frees-in-task_security-.patch
parent1cd8ab18abca96e4ee108f80225058d875b28347 (diff)
kernel: smack security backport from kernel 4
Here is the backport of all patches relating to smack support on kernel side. For more details, see file: meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/README Please note that patches are applied only if "smack" is in the ditro features. Here are the 2 lines to add in the local.conf OVERRIDES .= ":smack" DISTRO_FEATURES_append = " smack" Change-Id: I147a3532aec531f977d6ec34c576261835711f1e Signed-off-by: Yannick GICQUEL <yannick.gicquel@iot.bzh> Signed-off-by: José Bollo <jose.bollo@iot.bzh>
Diffstat (limited to 'meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/0052-smack-fix-possible-use-after-frees-in-task_security-.patch')
-rw-r--r--meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/0052-smack-fix-possible-use-after-frees-in-task_security-.patch253
1 files changed, 253 insertions, 0 deletions
diff --git a/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/0052-smack-fix-possible-use-after-frees-in-task_security-.patch b/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/0052-smack-fix-possible-use-after-frees-in-task_security-.patch
new file mode 100644
index 0000000..7486945
--- /dev/null
+++ b/meta-rcar-gen2/recipes-kernel/linux/linux-renesas/smack/0052-smack-fix-possible-use-after-frees-in-task_security-.patch
@@ -0,0 +1,253 @@
+From 7089ef9dcab89e60396bafb8c6cc0398f09da902 Mon Sep 17 00:00:00 2001
+From: Andrey Ryabinin <a.ryabinin@samsung.com>
+Date: Tue, 13 Jan 2015 18:52:40 +0300
+Subject: [PATCH 52/54] smack: fix possible use after frees in task_security()
+ callers
+
+We hit use after free on dereferncing pointer to task_smack struct in
+smk_of_task() called from smack_task_to_inode().
+
+task_security() macro uses task_cred_xxx() to get pointer to the task_smack.
+task_cred_xxx() could be used only for non-pointer members of task's
+credentials. It cannot be used for pointer members since what they point
+to may disapper after dropping RCU read lock.
+
+Mainly task_security() used this way:
+ smk_of_task(task_security(p))
+
+Intead of this introduce function smk_of_task_struct() which
+takes task_struct as argument and returns pointer to smk_known struct
+and do this under RCU read lock.
+Bogus task_security() macro is not used anymore, so remove it.
+
+KASan's report for this:
+
+ AddressSanitizer: use after free in smack_task_to_inode+0x50/0x70 at addr c4635600
+ =============================================================================
+ BUG kmalloc-64 (Tainted: PO): kasan error
+ -----------------------------------------------------------------------------
+
+ Disabling lock debugging due to kernel taint
+ INFO: Allocated in new_task_smack+0x44/0xd8 age=39 cpu=0 pid=1866
+ kmem_cache_alloc_trace+0x88/0x1bc
+ new_task_smack+0x44/0xd8
+ smack_cred_prepare+0x48/0x21c
+ security_prepare_creds+0x44/0x4c
+ prepare_creds+0xdc/0x110
+ smack_setprocattr+0x104/0x150
+ security_setprocattr+0x4c/0x54
+ proc_pid_attr_write+0x12c/0x194
+ vfs_write+0x1b0/0x370
+ SyS_write+0x5c/0x94
+ ret_fast_syscall+0x0/0x48
+ INFO: Freed in smack_cred_free+0xc4/0xd0 age=27 cpu=0 pid=1564
+ kfree+0x270/0x290
+ smack_cred_free+0xc4/0xd0
+ security_cred_free+0x34/0x3c
+ put_cred_rcu+0x58/0xcc
+ rcu_process_callbacks+0x738/0x998
+ __do_softirq+0x264/0x4cc
+ do_softirq+0x94/0xf4
+ irq_exit+0xbc/0x120
+ handle_IRQ+0x104/0x134
+ gic_handle_irq+0x70/0xac
+ __irq_svc+0x44/0x78
+ _raw_spin_unlock+0x18/0x48
+ sync_inodes_sb+0x17c/0x1d8
+ sync_filesystem+0xac/0xfc
+ vdfs_file_fsync+0x90/0xc0
+ vfs_fsync_range+0x74/0x7c
+ INFO: Slab 0xd3b23f50 objects=32 used=31 fp=0xc4635600 flags=0x4080
+ INFO: Object 0xc4635600 @offset=5632 fp=0x (null)
+
+ Bytes b4 c46355f0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
+ Object c4635600: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
+ Object c4635610: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
+ Object c4635620: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
+ Object c4635630: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
+ Redzone c4635640: bb bb bb bb ....
+ Padding c46356e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
+ Padding c46356f8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
+ CPU: 5 PID: 834 Comm: launchpad_prelo Tainted: PBO 3.10.30 #1
+ Backtrace:
+ [<c00233a4>] (dump_backtrace+0x0/0x158) from [<c0023dec>] (show_stack+0x20/0x24)
+ r7:c4634010 r6:d3b23f50 r5:c4635600 r4:d1002140
+ [<c0023dcc>] (show_stack+0x0/0x24) from [<c06d6d7c>] (dump_stack+0x20/0x28)
+ [<c06d6d5c>] (dump_stack+0x0/0x28) from [<c01c1d50>] (print_trailer+0x124/0x144)
+ [<c01c1c2c>] (print_trailer+0x0/0x144) from [<c01c1e88>] (object_err+0x3c/0x44)
+ r7:c4635600 r6:d1002140 r5:d3b23f50 r4:c4635600
+ [<c01c1e4c>] (object_err+0x0/0x44) from [<c01cac18>] (kasan_report_error+0x2b8/0x538)
+ r6:d1002140 r5:d3b23f50 r4:c6429cf8 r3:c09e1aa7
+ [<c01ca960>] (kasan_report_error+0x0/0x538) from [<c01c9430>] (__asan_load4+0xd4/0xf8)
+ [<c01c935c>] (__asan_load4+0x0/0xf8) from [<c031e168>] (smack_task_to_inode+0x50/0x70)
+ r5:c4635600 r4:ca9da000
+ [<c031e118>] (smack_task_to_inode+0x0/0x70) from [<c031af64>] (security_task_to_inode+0x3c/0x44)
+ r5:cca25e80 r4:c0ba9780
+ [<c031af28>] (security_task_to_inode+0x0/0x44) from [<c023d614>] (pid_revalidate+0x124/0x178)
+ r6:00000000 r5:cca25e80 r4:cbabe3c0 r3:00008124
+ [<c023d4f0>] (pid_revalidate+0x0/0x178) from [<c01db98c>] (lookup_fast+0x35c/0x43y4)
+ r9:c6429efc r8:00000101 r7:c079d940 r6:c6429e90 r5:c6429ed8 r4:c83c4148
+ [<c01db630>] (lookup_fast+0x0/0x434) from [<c01deec8>] (do_last.isra.24+0x1c0/0x1108)
+ [<c01ded08>] (do_last.isra.24+0x0/0x1108) from [<c01dff04>] (path_openat.isra.25+0xf4/0x648)
+ [<c01dfe10>] (path_openat.isra.25+0x0/0x648) from [<c01e1458>] (do_filp_open+0x3c/0x88)
+ [<c01e141c>] (do_filp_open+0x0/0x88) from [<c01ccb28>] (do_sys_open+0xf0/0x198)
+ r7:00000001 r6:c0ea2180 r5:0000000b r4:00000000
+ [<c01cca38>] (do_sys_open+0x0/0x198) from [<c01ccc00>] (SyS_open+0x30/0x34)
+ [<c01ccbd0>] (SyS_open+0x0/0x34) from [<c001db80>] (ret_fast_syscall+0x0/0x48)
+ Read of size 4 by thread T834:
+ Memory state around the buggy address:
+ c4635380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ c4635400: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
+ c4635480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ c4635500: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
+ c4635580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ >c4635600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ ^
+ c4635680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ c4635700: 00 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc
+ c4635780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ c4635800: 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc fc
+ c4635880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
+ ==================================================================
+
+Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
+Cc: <stable@vger.kernel.org>
+---
+ security/smack/smack.h | 10 ++++++++++
+ security/smack/smack_lsm.c | 24 +++++++++++++-----------
+ 2 files changed, 23 insertions(+), 11 deletions(-)
+
+diff --git a/security/smack/smack.h b/security/smack/smack.h
+index 7629eae..67ccb7b 100644
+--- a/security/smack/smack.h
++++ b/security/smack/smack.h
+@@ -299,6 +299,16 @@ static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
+ return tsp->smk_task;
+ }
+
++static inline struct smack_known *smk_of_task_struct(const struct task_struct *t)
++{
++ struct smack_known *skp;
++
++ rcu_read_lock();
++ skp = smk_of_task(__task_cred(t)->security);
++ rcu_read_unlock();
++ return skp;
++}
++
+ /*
+ * Present a pointer to the forked smack label entry in an task blob.
+ */
+diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
+index 12eb355..05ffb24 100644
+--- a/security/smack/smack_lsm.c
++++ b/security/smack/smack_lsm.c
+@@ -43,8 +43,6 @@
+ #include <linux/binfmts.h>
+ #include "smack.h"
+
+-#define task_security(task) (task_cred_xxx((task), security))
+-
+ #define TRANS_TRUE "TRUE"
+ #define TRANS_TRUE_SIZE 4
+
+@@ -123,7 +121,7 @@ static int smk_bu_current(char *note, struct smack_known *oskp,
+ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
+ {
+ struct task_smack *tsp = current_security();
+- struct task_smack *otsp = task_security(otp);
++ struct smack_known *smk_task = smk_of_task_struct(otp);
+ char acc[SMK_NUM_ACCESS_TYPE + 1];
+
+ if (rc <= 0)
+@@ -131,7 +129,7 @@ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
+
+ smk_bu_mode(mode, acc);
+ pr_info("Smack Bringup: (%s %s %s) %s to %s\n",
+- tsp->smk_task->smk_known, otsp->smk_task->smk_known, acc,
++ tsp->smk_task->smk_known, smk_task->smk_known, acc,
+ current->comm, otp->comm);
+ return 0;
+ }
+@@ -352,7 +350,8 @@ static int smk_ptrace_rule_check(struct task_struct *tracer,
+ saip = &ad;
+ }
+
+- tsp = task_security(tracer);
++ rcu_read_lock();
++ tsp = __task_cred(tracer)->security;
+ tracer_known = smk_of_task(tsp);
+
+ if ((mode & PTRACE_MODE_ATTACH) &&
+@@ -372,11 +371,14 @@ static int smk_ptrace_rule_check(struct task_struct *tracer,
+ tracee_known->smk_known,
+ 0, rc, saip);
+
++ rcu_read_unlock();
+ return rc;
+ }
+
+ /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
+ rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
++
++ rcu_read_unlock();
+ return rc;
+ }
+
+@@ -403,7 +405,7 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
+ if (rc != 0)
+ return rc;
+
+- skp = smk_of_task(task_security(ctp));
++ skp = smk_of_task_struct(ctp);
+
+ rc = smk_ptrace_rule_check(current, skp, mode, __func__);
+ return rc;
+@@ -1831,7 +1833,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access,
+ const char *caller)
+ {
+ struct smk_audit_info ad;
+- struct smack_known *skp = smk_of_task(task_security(p));
++ struct smack_known *skp = smk_of_task_struct(p);
+ int rc;
+
+ smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
+@@ -1884,7 +1886,7 @@ static int smack_task_getsid(struct task_struct *p)
+ */
+ static void smack_task_getsecid(struct task_struct *p, u32 *secid)
+ {
+- struct smack_known *skp = smk_of_task(task_security(p));
++ struct smack_known *skp = smk_of_task_struct(p);
+
+ *secid = skp->smk_secid;
+ }
+@@ -1991,7 +1993,7 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info,
+ {
+ struct smk_audit_info ad;
+ struct smack_known *skp;
+- struct smack_known *tkp = smk_of_task(task_security(p));
++ struct smack_known *tkp = smk_of_task_struct(p);
+ int rc;
+
+ smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
+@@ -2045,7 +2047,7 @@ static int smack_task_wait(struct task_struct *p)
+ static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
+ {
+ struct inode_smack *isp = inode->i_security;
+- struct smack_known *skp = smk_of_task(task_security(p));
++ struct smack_known *skp = smk_of_task_struct(p);
+
+ isp->smk_inode = skp;
+ }
+@@ -3227,7 +3229,7 @@ unlockandout:
+ */
+ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
+ {
+- struct smack_known *skp = smk_of_task(task_security(p));
++ struct smack_known *skp = smk_of_task_struct(p);
+ char *cp;
+ int slen;
+
+--
+2.1.4
+