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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-10 12:59:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-10 12:59:56 -0700
commit87ad46e601340394cd75c1c79b19ca906f82c543 (patch)
tree33fc81013077804e4bdea9465de66144ca1d025b
parent75bdc9293dfd1c1dea297bbc65b37c7f6dcb2bd6 (diff)
parent63f818f46af9f8b3f17b9695501e8d08959feb60 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull proc fix from Eric Biederman: "A brown paper bag slipped through my proc changes, and syzcaller caught it when the code ended up in your tree. I have opted to fix it the simplest cleanest way I know how, so there is no reasonable chance for the bug to repeat" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Use a dedicated lock in struct pid
-rw-r--r--fs/proc/base.c10
-rw-r--r--include/linux/pid.h1
-rw-r--r--kernel/pid.c1
3 files changed, 7 insertions, 5 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 74f948a6b621..6042b646ab27 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1839,9 +1839,9 @@ void proc_pid_evict_inode(struct proc_inode *ei)
struct pid *pid = ei->pid;
if (S_ISDIR(ei->vfs_inode.i_mode)) {
- spin_lock(&pid->wait_pidfd.lock);
+ spin_lock(&pid->lock);
hlist_del_init_rcu(&ei->sibling_inodes);
- spin_unlock(&pid->wait_pidfd.lock);
+ spin_unlock(&pid->lock);
}
put_pid(pid);
@@ -1877,9 +1877,9 @@ struct inode *proc_pid_make_inode(struct super_block * sb,
/* Let the pid remember us for quick removal */
ei->pid = pid;
if (S_ISDIR(mode)) {
- spin_lock(&pid->wait_pidfd.lock);
+ spin_lock(&pid->lock);
hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
- spin_unlock(&pid->wait_pidfd.lock);
+ spin_unlock(&pid->lock);
}
task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
@@ -3273,7 +3273,7 @@ static const struct inode_operations proc_tgid_base_inode_operations = {
void proc_flush_pid(struct pid *pid)
{
- proc_invalidate_siblings_dcache(&pid->inodes, &pid->wait_pidfd.lock);
+ proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
put_pid(pid);
}
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 01a0d4e28506..cc896f0fc4e3 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -60,6 +60,7 @@ struct pid
{
refcount_t count;
unsigned int level;
+ spinlock_t lock;
/* lists of tasks that use this pid */
struct hlist_head tasks[PIDTYPE_MAX];
struct hlist_head inodes;
diff --git a/kernel/pid.c b/kernel/pid.c
index bc21c0fb26d8..c835b844aca7 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -256,6 +256,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,
get_pid_ns(ns);
refcount_set(&pid->count, 1);
+ spin_lock_init(&pid->lock);
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);