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authorSteven Rostedt (Google)2024-01-31 13:49:19 -0500
committerSteven Rostedt (Google)2024-01-31 14:15:47 -0500
commitd81786f53aec14fd4d56263145a0635afbc64617 (patch)
tree3a8e0d8fde941c440ec21ce60e6e4319dbc1b583
parent66bbea9ed6446b8471d365a22734dc00556c4785 (diff)
tracefs: Zero out the tracefs_inode when allocating it
eventfs uses the tracefs_inode and assumes that it's already initialized to zero. That is, it doesn't set fields to zero (like ti->private) after getting its tracefs_inode. This causes bugs due to stale values. Just initialize the entire structure to zero on allocation so there isn't any more surprises. This is a partial fix to access to ti->private. The assignment still needs to be made before the dentry is instantiated. Link: https://lore.kernel.org/linux-trace-kernel/20240131185512.315825944@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Ajay Kaher <ajay.kaher@broadcom.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202401291043.e62e89dc-oliver.sang@intel.com Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-rw-r--r--fs/tracefs/inode.c6
-rw-r--r--fs/tracefs/internal.h3
2 files changed, 6 insertions, 3 deletions
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index e1b172c0e091..888e42087847 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -38,8 +38,6 @@ static struct inode *tracefs_alloc_inode(struct super_block *sb)
if (!ti)
return NULL;
- ti->flags = 0;
-
return &ti->vfs_inode;
}
@@ -779,7 +777,11 @@ static void init_once(void *foo)
{
struct tracefs_inode *ti = (struct tracefs_inode *) foo;
+ /* inode_init_once() calls memset() on the vfs_inode portion */
inode_init_once(&ti->vfs_inode);
+
+ /* Zero out the rest */
+ memset_after(ti, 0, vfs_inode);
}
static int __init tracefs_init(void)
diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
index 91c2bf0b91d9..7d84349ade87 100644
--- a/fs/tracefs/internal.h
+++ b/fs/tracefs/internal.h
@@ -11,9 +11,10 @@ enum {
};
struct tracefs_inode {
+ struct inode vfs_inode;
+ /* The below gets initialized with memset_after(ti, 0, vfs_inode) */
unsigned long flags;
void *private;
- struct inode vfs_inode;
};
/*