From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4EBB01534FB; Tue, 23 Jul 2024 15:50:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721749841; cv=none; b=fwsDoMzwuKyjgNEEBD6Z3wqKKy9JyK8qdUllAtXV2XgWxqF8RCosgDt7ywCZG9n8G4FrH50OFntEOvi292lOBsVaqh5Okj4qtL8c0o5y+EGNsowsFpaH2yoKP41WT3LbofjxpUFnOGcLkI1lnFnXRkEAneF6ayJdB1XlC5/Uyrk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721749841; c=relaxed/simple; bh=TnGMsrJ4pto9VumueOBg6ah9e5LJdE4tr9oJecz4Ptg=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=JwkDoDK2u9vDojfpn2oE1da4RChHmTCakOQoKXpt/m0VJUgAwPMnFLAPx9+WcXouCkMkxO6DojyoyADTwOWt+K4GjRDQN0sdOtGqb7L2UQXjQEm4+RsZdIqko5E93vsvh8REuxf0cBSbm6hu/y16DC0EGF2wfgLXVozdlWP4YJg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oTwjMndw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oTwjMndw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C7EAC4AF0E; Tue, 23 Jul 2024 15:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721749841; bh=TnGMsrJ4pto9VumueOBg6ah9e5LJdE4tr9oJecz4Ptg=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=oTwjMndwy4XRxPmDNLdjyU0pGmn1DtwsL+TZCskHHCJ6XDLRUVhrBn+HLAA5GXf7M f/SW0AsP9rxp0Fsm2jBgQIG3jmoxx2D1oEFadCmMSououeezWNYb0nwIWFINKteTgc 1FnKFuPCvEzAeFF38xLB6AqXBZzIdjCcfqY6UxA5AAb+oXjHFMKbkfWUOi1SMfQbV6 i+01PC2rwajbj8osUZey5bkN4j7uU9XXUFNPt+hFWPYBlWYoYfAB/R+ANhQyRGp175 UGnyxA11PcBezhTv6GNdCPmG8JrF5f6b6ythiGmUOxkZK7YGXWYjoDca+P7ago3q4G ggYZls6eAK2wg== Message-ID: <0616b6be151e2063627fb7f22100b9d3407aceb3.camel@kernel.org> Subject: Re: [PATCH] filelock: Fix fcntl/close race recovery compat path From: Jeff Layton To: Jann Horn , Alexander Viro , Christian Brauner , Jan Kara , Chuck Lever , Alexander Aring Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org Date: Tue, 23 Jul 2024 11:50:37 -0400 In-Reply-To: <20240723-fs-lock-recover-compatfix-v1-1-148096719529@google.com> References: <20240723-fs-lock-recover-compatfix-v1-1-148096719529@google.com> Autocrypt: addr=jlayton@kernel.org; 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charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.4 (3.50.4-1.fc39) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Tue, 2024-07-23 at 17:03 +0200, Jann Horn wrote: > When I wrote commit 3cad1bc01041 ("filelock: Remove locks reliably when > fcntl/close race is detected"), I missed that there are two copies of the > code I was patching: The normal version, and the version for 64-bit offse= ts > on 32-bit kernels. > Thanks to Greg KH for stumbling over this while doing the stable > backport... >=20 > Apply exactly the same fix to the compat path for 32-bit kernels. >=20 > Fixes: c293621bbf67 ("[PATCH] stale POSIX lock handling") > Cc: stable@kernel.org > Link: https://bugs.chromium.org/p/project-zero/issues/detail?id=3D2563 > Signed-off-by: Jann Horn > --- > =C2=A0fs/locks.c | 9 ++++----- > =C2=A01 file changed, 4 insertions(+), 5 deletions(-) >=20 > diff --git a/fs/locks.c b/fs/locks.c > index bdd94c32256f..9afb16e0683f 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -2570,8 +2570,9 @@ int fcntl_setlk64(unsigned int fd, struct file *fil= p, unsigned int cmd, > =C2=A0 error =3D do_lock_file_wait(filp, cmd, file_lock); > =C2=A0 > =C2=A0 /* > - * Attempt to detect a close/fcntl race and recover by releasing the > - * lock that was just acquired. There is no need to do that when we're > + * Detect close/fcntl races and recover by zapping all POSIX locks > + * associated with this file and our files_struct, just like on > + * filp_flush(). There is no need to do that when we're > =C2=A0 * unlocking though, or for OFD locks. > =C2=A0 */ > =C2=A0 if (!error && file_lock->c.flc_type !=3D F_UNLCK && > @@ -2586,9 +2587,7 @@ int fcntl_setlk64(unsigned int fd, struct file *fil= p, unsigned int cmd, > =C2=A0 f =3D files_lookup_fd_locked(files, fd); > =C2=A0 spin_unlock(&files->file_lock); > =C2=A0 if (f !=3D filp) { > - file_lock->c.flc_type =3D F_UNLCK; > - error =3D do_lock_file_wait(filp, cmd, file_lock); > - WARN_ON_ONCE(error); > + locks_remove_posix(filp, files); > =C2=A0 error =3D -EBADF; > =C2=A0 } > =C2=A0 } >=20 > --- > base-commit: 66ebbdfdeb093e097399b1883390079cd4c3022b > change-id: 20240723-fs-lock-recover-compatfix-cf2cbab343d1 Doh! Good catch. Reviewed-by: Jeff Layton