--- /dev/null
+From 3f9aec7610b39521c7c69d754de7265f6994c194 Mon Sep 17 00:00:00 2001
+From: Jean Delvare <khali@linux-fr.org>
+Date: Tue, 14 Jan 2014 15:59:55 +0100
+Subject: hwmon: (coretemp) Fix truncated name of alarm attributes
+
+From: Jean Delvare <khali@linux-fr.org>
+
+commit 3f9aec7610b39521c7c69d754de7265f6994c194 upstream.
+
+When the core number exceeds 9, the size of the buffer storing the
+alarm attribute name is insufficient and the attribute name is
+truncated. This causes libsensors to skip these attributes as the
+truncated name is not recognized.
+
+Reported-by: Andreas Hollmann <hollmann@in.tum.de>
+Signed-off-by: Jean Delvare <khali@linux-fr.org>
+Signed-off-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/hwmon/coretemp.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/hwmon/coretemp.c
++++ b/drivers/hwmon/coretemp.c
+@@ -53,7 +53,7 @@ MODULE_PARM_DESC(tjmax, "TjMax value in
+
+ #define BASE_SYSFS_ATTR_NO 2 /* Sysfs Base attr no for coretemp */
+ #define NUM_REAL_CORES 32 /* Number of Real cores per cpu */
+-#define CORETEMP_NAME_LENGTH 17 /* String Length of attrs */
++#define CORETEMP_NAME_LENGTH 19 /* String Length of attrs */
+ #define MAX_CORE_ATTRS 4 /* Maximum no of basic attrs */
+ #define TOTAL_ATTRS (MAX_CORE_ATTRS + 1)
+ #define MAX_CORE_DATA (NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
--- /dev/null
+From 3dc91d4338d698ce77832985f9cb183d8eeaf6be Mon Sep 17 00:00:00 2001
+From: Steven Rostedt <rostedt@goodmis.org>
+Date: Thu, 9 Jan 2014 21:46:34 -0500
+Subject: SELinux: Fix possible NULL pointer dereference in selinux_inode_permission()
+
+From: Steven Rostedt <rostedt@goodmis.org>
+
+commit 3dc91d4338d698ce77832985f9cb183d8eeaf6be upstream.
+
+While running stress tests on adding and deleting ftrace instances I hit
+this bug:
+
+ BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
+ IP: selinux_inode_permission+0x85/0x160
+ PGD 63681067 PUD 7ddbe067 PMD 0
+ Oops: 0000 [#1] PREEMPT
+ CPU: 0 PID: 5634 Comm: ftrace-test-mki Not tainted 3.13.0-rc4-test-00033-gd2a6dde-dirty #20
+ Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
+ task: ffff880078375800 ti: ffff88007ddb0000 task.ti: ffff88007ddb0000
+ RIP: 0010:[<ffffffff812d8bc5>] [<ffffffff812d8bc5>] selinux_inode_permission+0x85/0x160
+ RSP: 0018:ffff88007ddb1c48 EFLAGS: 00010246
+ RAX: 0000000000000000 RBX: 0000000000800000 RCX: ffff88006dd43840
+ RDX: 0000000000000001 RSI: 0000000000000081 RDI: ffff88006ee46000
+ RBP: ffff88007ddb1c88 R08: 0000000000000000 R09: ffff88007ddb1c54
+ R10: 6e6576652f6f6f66 R11: 0000000000000003 R12: 0000000000000000
+ R13: 0000000000000081 R14: ffff88006ee46000 R15: 0000000000000000
+ FS: 00007f217b5b6700(0000) GS:ffffffff81e21000(0000) knlGS:0000000000000000
+ CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033^M
+ CR2: 0000000000000020 CR3: 000000006a0fe000 CR4: 00000000000007f0
+ Call Trace:
+ security_inode_permission+0x1c/0x30
+ __inode_permission+0x41/0xa0
+ inode_permission+0x18/0x50
+ link_path_walk+0x66/0x920
+ path_openat+0xa6/0x6c0
+ do_filp_open+0x43/0xa0
+ do_sys_open+0x146/0x240
+ SyS_open+0x1e/0x20
+ system_call_fastpath+0x16/0x1b
+ Code: 84 a1 00 00 00 81 e3 00 20 00 00 89 d8 83 c8 02 40 f6 c6 04 0f 45 d8 40 f6 c6 08 74 71 80 cf 02 49 8b 46 38 4c 8d 4d cc 45 31 c0 <0f> b7 50 20 8b 70 1c 48 8b 41 70 89 d9 8b 78 04 e8 36 cf ff ff
+ RIP selinux_inode_permission+0x85/0x160
+ CR2: 0000000000000020
+
+Investigating, I found that the inode->i_security was NULL, and the
+dereference of it caused the oops.
+
+in selinux_inode_permission():
+
+ isec = inode->i_security;
+
+ rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
+
+Note, the crash came from stressing the deletion and reading of debugfs
+files. I was not able to recreate this via normal files. But I'm not
+sure they are safe. It may just be that the race window is much harder
+to hit.
+
+What seems to have happened (and what I have traced), is the file is
+being opened at the same time the file or directory is being deleted.
+As the dentry and inode locks are not held during the path walk, nor is
+the inodes ref counts being incremented, there is nothing saving these
+structures from being discarded except for an rcu_read_lock().
+
+The rcu_read_lock() protects against freeing of the inode, but it does
+not protect freeing of the inode_security_struct. Now if the freeing of
+the i_security happens with a call_rcu(), and the i_security field of
+the inode is not changed (it gets freed as the inode gets freed) then
+there will be no issue here. (Linus Torvalds suggested not setting the
+field to NULL such that we do not need to check if it is NULL in the
+permission check).
+
+Note, this is a hack, but it fixes the problem at hand. A real fix is
+to restructure the destroy_inode() to call all the destructor handlers
+from the RCU callback. But that is a major job to do, and requires a
+lot of work. For now, we just band-aid this bug with this fix (it
+works), and work on a more maintainable solution in the future.
+
+Link: http://lkml.kernel.org/r/20140109101932.0508dec7@gandalf.local.home
+Link: http://lkml.kernel.org/r/20140109182756.17abaaa8@gandalf.local.home
+
+Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ security/selinux/hooks.c | 20 ++++++++++++++++++--
+ security/selinux/include/objsec.h | 5 ++++-
+ 2 files changed, 22 insertions(+), 3 deletions(-)
+
+--- a/security/selinux/hooks.c
++++ b/security/selinux/hooks.c
+@@ -218,6 +218,14 @@ static int inode_alloc_security(struct i
+ return 0;
+ }
+
++static void inode_free_rcu(struct rcu_head *head)
++{
++ struct inode_security_struct *isec;
++
++ isec = container_of(head, struct inode_security_struct, rcu);
++ kmem_cache_free(sel_inode_cache, isec);
++}
++
+ static void inode_free_security(struct inode *inode)
+ {
+ struct inode_security_struct *isec = inode->i_security;
+@@ -228,8 +236,16 @@ static void inode_free_security(struct i
+ list_del_init(&isec->list);
+ spin_unlock(&sbsec->isec_lock);
+
+- inode->i_security = NULL;
+- kmem_cache_free(sel_inode_cache, isec);
++ /*
++ * The inode may still be referenced in a path walk and
++ * a call to selinux_inode_permission() can be made
++ * after inode_free_security() is called. Ideally, the VFS
++ * wouldn't do this, but fixing that is a much harder
++ * job. For now, simply free the i_security via RCU, and
++ * leave the current inode->i_security pointer intact.
++ * The inode will be freed after the RCU grace period too.
++ */
++ call_rcu(&isec->rcu, inode_free_rcu);
+ }
+
+ static int file_alloc_security(struct file *file)
+--- a/security/selinux/include/objsec.h
++++ b/security/selinux/include/objsec.h
+@@ -38,7 +38,10 @@ struct task_security_struct {
+
+ struct inode_security_struct {
+ struct inode *inode; /* back pointer to inode object */
+- struct list_head list; /* list of inode_security_struct */
++ union {
++ struct list_head list; /* list of inode_security_struct */
++ struct rcu_head rcu; /* for freeing the inode_security_struct */
++ };
+ u32 task_sid; /* SID of creating task */
+ u32 sid; /* SID of this object */
+ u16 sclass; /* security class of this object */
projects / thirdparty / kernel / stable-queue.git / commitdiff
