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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-10 12:10:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-10 12:10:02 -0700 |
| commit | f5364c150aa645b3d7daa21b5c0b9feaa1c9cd6d (patch) | |
| tree | a7445608f147d3a7214382c5db3f5d721ee99369 | |
| parent | Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux (diff) | |
| parent | sched: panic on corrupted stack end (diff) | |
| download | linux-dev-f5364c150aa645b3d7daa21b5c0b9feaa1c9cd6d.tar.xz linux-dev-f5364c150aa645b3d7daa21b5c0b9feaa1c9cd6d.zip | |
Merge branch 'stacking-fixes' (vfs stacking fixes from Jann)
Merge filesystem stacking fixes from Jann Horn.
* emailed patches from Jann Horn <jannh@google.com>:
sched: panic on corrupted stack end
ecryptfs: forbid opening files without mmap handler
proc: prevent stacking filesystems on top
| -rw-r--r-- | fs/ecryptfs/kthread.c | 13 | ||||
| -rw-r--r-- | fs/proc/root.c | 7 | ||||
| -rw-r--r-- | kernel/sched/core.c | 3 |
3 files changed, 20 insertions, 3 deletions
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c index 866bb18efefe..e818f5ac7a26 100644 --- a/fs/ecryptfs/kthread.c +++ b/fs/ecryptfs/kthread.c @@ -25,6 +25,7 @@ #include <linux/slab.h> #include <linux/wait.h> #include <linux/mount.h> +#include <linux/file.h> #include "ecryptfs_kernel.h" struct ecryptfs_open_req { @@ -147,7 +148,7 @@ int ecryptfs_privileged_open(struct file **lower_file, flags |= IS_RDONLY(d_inode(lower_dentry)) ? O_RDONLY : O_RDWR; (*lower_file) = dentry_open(&req.path, flags, cred); if (!IS_ERR(*lower_file)) - goto out; + goto have_file; if ((flags & O_ACCMODE) == O_RDONLY) { rc = PTR_ERR((*lower_file)); goto out; @@ -165,8 +166,16 @@ int ecryptfs_privileged_open(struct file **lower_file, mutex_unlock(&ecryptfs_kthread_ctl.mux); wake_up(&ecryptfs_kthread_ctl.wait); wait_for_completion(&req.done); - if (IS_ERR(*lower_file)) + if (IS_ERR(*lower_file)) { rc = PTR_ERR(*lower_file); + goto out; + } +have_file: + if ((*lower_file)->f_op->mmap == NULL) { + fput(*lower_file); + *lower_file = NULL; + rc = -EMEDIUMTYPE; + } out: return rc; } diff --git a/fs/proc/root.c b/fs/proc/root.c index 55bc7d6c8aac..06702783bf40 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -121,6 +121,13 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, if (IS_ERR(sb)) return ERR_CAST(sb); + /* + * procfs isn't actually a stacking filesystem; however, there is + * too much magic going on inside it to permit stacking things on + * top of it + */ + sb->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH; + if (!proc_parse_options(options, ns)) { deactivate_locked_super(sb); return ERR_PTR(-EINVAL); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 385c947482e1..017d5394f5dc 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3170,7 +3170,8 @@ static noinline void __schedule_bug(struct task_struct *prev) static inline void schedule_debug(struct task_struct *prev) { #ifdef CONFIG_SCHED_STACK_END_CHECK - BUG_ON(task_stack_end_corrupted(prev)); + if (task_stack_end_corrupted(prev)) + panic("corrupted stack end detected inside scheduler\n"); #endif if (unlikely(in_atomic_preempt_off())) { |