From: sashiko-bot@kernel.org
To: "Christian Brauner" <brauner@kernel.org>
Cc: linux-ext4@vger.kernel.org, tytso@mit.edu,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH 7/8] ntfs3: free the sbi after a grace period
Date: Fri, 09 Oct 2026 22:03:48 +0000 [thread overview]
Message-ID: <sashiko-outbox-166121@kernel.org> (raw)
In-Reply-To: <20261009-work-fixes-rcu-v1-7-7446d2d335e6@kernel.org>
> If the "nocase" mount option ntfs3 uses custom hash and dentry compare
> functions. Both access ntfs3 superblock private information in rcu
> pathwalk. ntfs_put_super() and ntfs3_kill_sb() drop the info without any
> rcu delay. A lookup that's still inside the filesystem when the last
> reference to the mount is dropped causes a UAF. With a pathwalk held up
> in ntfs_d_hash() while the last reference to the mount goes away:
>
> BUG: KASAN: slab-use-after-free in ntfs_nls_to_utf16+0x752/0x940
> Read of size 8 at addr ff1100010453c850 by task walker/99
> Call Trace:
> <TASK>
> ntfs_nls_to_utf16+0x752/0x940
> ntfs_d_hash+0x22b/0x500
> link_path_walk+0x11ad/0x1d30
> path_lookupat+0x63/0xb00
> [ ... ]
> holding the lock on the same cpu.
>
> Fixes: a3a956c78efa ("fs/ntfs3: Add option "nocase"")
> Cc: stable@vger.kernel.org
> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261009-work-fixes-rcu-v1-0-7446d2d335e6@kernel.org?part=7
next prev parent reply other threads:[~2026-10-09 22:03 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-09 21:51 [PATCH 0/8] fs: fix a range of UAFs during rcu pathwalk caused by non-rcu frees Christian Brauner
2026-10-09 21:51 ` [PATCH 1/8] ext4: free the sbi after a grace period Christian Brauner
2026-10-09 22:04 ` sashiko-bot
2026-10-13 12:14 ` Jan Kara
2026-10-09 21:51 ` [PATCH 2/8] afs: free the super info " Christian Brauner
2026-10-09 22:07 ` sashiko-bot
2026-10-10 12:54 ` Christian Brauner
2026-10-09 21:51 ` [PATCH 3/8] 9p: free the session " Christian Brauner
2026-10-09 22:03 ` sashiko-bot
2026-10-09 21:51 ` [PATCH 4/8] eventfs: free the eventfs_inode after an rcu grace period too Christian Brauner
2026-10-09 21:58 ` sashiko-bot
2026-10-09 21:51 ` [PATCH 5/8] ipc: drop the mqueue mount with kern_unmount() on setup failure Christian Brauner
2026-10-09 22:00 ` sashiko-bot
2026-10-09 21:51 ` [PATCH 6/8] unicode: free the map after a grace period Christian Brauner
2026-10-09 22:04 ` sashiko-bot
2026-10-13 12:16 ` Jan Kara
2026-10-09 21:51 ` [PATCH 7/8] ntfs3: free the sbi " Christian Brauner
2026-10-09 22:03 ` sashiko-bot [this message]
2026-10-09 21:51 ` [PATCH 8/8] ntfs3: free replaced mount options " Christian Brauner
2026-10-09 22:02 ` sashiko-bot
2026-10-10 12:55 ` Christian Brauner
2026-10-12 10:36 ` [PATCH 0/8] fs: fix a range of UAFs during rcu pathwalk caused by non-rcu frees Jan Kara
2026-10-12 10:42 ` Christian Brauner
2026-10-13 10:47 ` Jan Kara
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