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From: Chuck Lever <cel@kernel.org>
To: NeilBrown <neil@brown.name>, Jeff Layton <jlayton@kernel.org>,
	Olga Kornievskaia <okorniev@redhat.com>,
	Dai Ngo <dai.ngo@oracle.com>, Tom Talpey <tom@talpey.com>
Cc: <linux-nfs@vger.kernel.org>, Chuck Lever <chuck.lever@oracle.com>
Subject: [PATCH v3 0/5] Fix unwanted memory overwrites
Date: Fri, 10 Oct 2025 09:56:18 -0400	[thread overview]
Message-ID: <20251010135623.1723-1-cel@kernel.org> (raw)

From: Chuck Lever <chuck.lever@oracle.com>

<rtm@csail.mit.edu> reported some memory overwrites that can be
triggered by NFS client input. I was able to observe overwrites
by enabling KASAN and running his reproducer [1].

NFSD caches COMPOUNDs containing only a single SEQUENCE operation
whether the client requests it to or not, in order to work around a
quirk in the NFSv4.1 protocol. However, the predicate that
identifies solo SEQUENCE operations was incorrect.

Changes since v2:
* Never cache a COMPOUND if SEQUENCE fails
* Enable caching of solo SEQUENCE operations again
* Reserve enough slot replay cache space to cache solo SEQUENCE

Changes since v1:
* Reordered patches
* Disable caching of solo SEQUENCE operations
* Additional clean up

Chuck Lever (5):
  NFSD: Skip close replay processing if XDR encoding fails
  NFSD: Fix the "is this a solo SEQUENCE" predicate
  nfsd: Never cache a COMPOUND when the SEQUENCE operation fails
  NFSD: Increase minimum size of slot replay cache
  NFSD: Move nfsd4_cache_this()

 fs/nfsd/nfs4state.c | 45 +++++++++++++++++++++++++++++++++++++++------
 fs/nfsd/nfs4xdr.c   |  3 +--
 fs/nfsd/xdr4.h      | 21 ---------------------
 3 files changed, 40 insertions(+), 29 deletions(-)

-- 
2.51.0


             reply	other threads:[~2025-10-10 13:56 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-10 13:56 Chuck Lever [this message]
2025-10-10 13:56 ` [PATCH v3 1/5] NFSD: Skip close replay processing if XDR encoding fails Chuck Lever
2025-10-10 13:56 ` [PATCH v3 2/5] NFSD: Fix the "is this a solo SEQUENCE" predicate Chuck Lever
2025-10-11  0:26   ` NeilBrown
2025-10-10 13:56 ` [PATCH v3 3/5] nfsd: Never cache a COMPOUND when the SEQUENCE operation fails Chuck Lever
2025-10-10 15:19   ` Jeff Layton
2025-10-11  0:38   ` NeilBrown
2025-10-10 13:56 ` [PATCH v3 4/5] NFSD: Increase minimum size of slot replay cache Chuck Lever
2025-10-10 15:22   ` Jeff Layton
2025-10-11  0:04   ` NeilBrown
2025-10-10 13:56 ` [PATCH v3 5/5] NFSD: Move nfsd4_cache_this() Chuck Lever

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