From: "Arnd Bergmann" <arnd@arndb.de>
To: moonafterrain@outlook.com,
"Madhavan Srinivasan" <maddy@linux.ibm.com>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Christophe Leroy" <chleroy@kernel.org>,
"Paul Mackerras" <paulus@ozlabs.org>,
"Alexander Viro" <viro@zeniv.linux.org.uk>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
"Yuhao Jiang" <danisjiang@gmail.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 4/6] powerpc/spufs: check permissions in spufs_setattr()
Date: Mon, 03 Aug 2026 11:16:56 +0200 [thread overview]
Message-ID: <9ff071ad-1f14-4160-8e1e-cc3b48c677f1@app.fastmail.com> (raw)
In-Reply-To: <20260802-fixes-v1-4-7368423440f4@outlook.com>
On Sun, Aug 2, 2026, at 17:51, Junrui Luo via B4 Relay wrote:
> From: Junrui Luo <moonafterrain@outlook.com>
>
> spufs_setattr() applies the caller's attributes with setattr_copy() but
> never calls setattr_prepare(). notify_change() leaves that to the
> filesystem: it runs only may_setattr(), while inode_owner_or_capable()
> and the CAP_CHOWN test live inside setattr_prepare(). setattr_copy()
> performs no checking of its own.
>
> The handler is installed for every regular spufs file, so mode and
> ownership of another user's context files can be changed without the
> usual authorization.
>
> Call setattr_prepare() before setattr_copy(). The existing ATTR_SIZE
> test stays ahead of it so that resizing a spufs file keeps returning
> -EINVAL. &nop_mnt_idmap matches the adjacent setattr_copy() call.
>
> Fixes: 67207b9664a8 ("[PATCH] spufs: The SPU file system, base")
> Reported-by: Yuhao Jiang <danisjiang@gmail.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
next prev parent reply other threads:[~2026-08-03 9:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-02 15:51 [PATCH 0/6] powerpc/spufs: assorted fixes Junrui Luo via B4 Relay
2026-08-02 15:51 ` [PATCH 1/6] powerpc/spufs: fix spu_context leak in coredump Junrui Luo via B4 Relay
2026-08-03 9:05 ` Arnd Bergmann
2026-08-02 15:51 ` [PATCH 2/6] powerpc/spufs: don't leak kernel stack via spu_run Junrui Luo via B4 Relay
2026-08-03 9:09 ` Arnd Bergmann
2026-08-02 15:51 ` [PATCH 3/6] powerpc/spufs: bound NPC against local store size Junrui Luo via B4 Relay
2026-08-03 9:14 ` Arnd Bergmann
2026-08-04 6:30 ` Junrui Luo
2026-08-02 15:51 ` [PATCH 4/6] powerpc/spufs: check permissions in spufs_setattr() Junrui Luo via B4 Relay
2026-08-03 9:16 ` Arnd Bergmann [this message]
2026-08-02 15:51 ` [PATCH 5/6] powerpc/spufs: fix deadlock on gang creation failure Junrui Luo via B4 Relay
2026-08-02 15:51 ` [PATCH 6/6] powerpc/spufs: don't hold state_mutex during user access Junrui Luo via B4 Relay
2026-08-03 9:26 ` Arnd Bergmann
2026-08-03 9:28 ` [PATCH 0/6] powerpc/spufs: assorted fixes Arnd Bergmann
2026-08-03 9:59 ` Junrui Luo
2026-08-03 10:18 ` Arnd Bergmann
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