The patch titled
Fix race between proc_readdir and remove_proc_entry
has been removed from the -mm tree. Its filename was
fix-race-between-proc_readdir-and-remove_proc_entry.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Fix race between proc_readdir and remove_proc_entry
From: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Fix the following race:
proc_readdir remove_proc_entry
============ =================
spin_lock(&proc_subdir_lock);
[choose PDE to start filldir from]
spin_unlock(&proc_subdir_lock);
spin_lock(&proc_subdir_lock);
[find PDE]
[free PDE, refcount is 0]
spin_unlock(&proc_subdir_lock);
/* boom */
if (filldir(dirent, de->name, ...
[de_put on error path --adobriyan]
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/generic.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff -puN fs/proc/generic.c~fix-race-between-proc_readdir-and-remove_proc_entry fs/proc/generic.c
--- a/fs/proc/generic.c~fix-race-between-proc_readdir-and-remove_proc_entry
+++ a/fs/proc/generic.c
@@ -478,14 +478,21 @@ int proc_readdir(struct file * filp,
}
do {
+ struct proc_dir_entry *next;
+
/* filldir passes info to user space */
+ de_get(de);
spin_unlock(&proc_subdir_lock);
if (filldir(dirent, de->name, de->namelen, filp->f_pos,
- de->low_ino, de->mode >> 12) < 0)
+ de->low_ino, de->mode >> 12) < 0) {
+ de_put(de);
goto out;
+ }
spin_lock(&proc_subdir_lock);
filp->f_pos++;
- de = de->next;
+ next = de->next;
+ de_put(de);
+ de = next;
} while (de);
spin_unlock(&proc_subdir_lock);
}
_
Patches currently in -mm which might be from djwong@xxxxxxxxxx are
origin.patch
-
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