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authorJeff Layton <[email protected]>2024-07-02 18:44:48 -0400
committerChristian Brauner <[email protected]>2024-07-05 18:40:44 +0200
commit1b3ec4f7c03d4b07bad70697d7e2f4088d2cfe92 (patch)
treebcb611bcaf879bc05baff2528c8ea0a7660390af
parenteeb17984e88858a5a324844083709f1c6425333c (diff)
filelock: fix potential use-after-free in posix_lock_inode
Light Hsieh reported a KASAN UAF warning in trace_posix_lock_inode(). The request pointer had been changed earlier to point to a lock entry that was added to the inode's list. However, before the tracepoint could fire, another task raced in and freed that lock. Fix this by moving the tracepoint inside the spinlock, which should ensure that this doesn't happen. Fixes: 74f6f5912693 ("locks: fix KASAN: use-after-free in trace_event_raw_event_filelock_lock") Link: https://lore.kernel.org/linux-fsdevel/[email protected]/ Reported-by: Light Hsieh (謝明燈) <[email protected]> Signed-off-by: Jeff Layton <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Alexander Aring <[email protected]> Signed-off-by: Christian Brauner <[email protected]>
-rw-r--r--fs/locks.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/locks.c b/fs/locks.c
index 90c8746874de..2a445776dae3 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1367,9 +1367,9 @@ retry:
locks_wake_up_blocks(&left->c);
}
out:
+ trace_posix_lock_inode(inode, request, error);
spin_unlock(&ctx->flc_lock);
percpu_up_read(&file_rwsem);
- trace_posix_lock_inode(inode, request, error);
/*
* Free any unused locks.
*/