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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-nfs@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 21/31] NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow
Date: Wed, 30 Dec 2020 08:03:03 -0500	[thread overview]
Message-ID: <20201230130314.3636961-21-sashal@kernel.org> (raw)
In-Reply-To: <20201230130314.3636961-1-sashal@kernel.org>

From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ Upstream commit 503b934a752f7e789a5f33217520e0a79f3096ac ]

Expanding the READ_PLUS extents can cause the read buffer to overflow.
If it does, then don't error, but just exit early.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/nfs42xdr.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 8432bd6b95f08..c078f88552695 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -1019,29 +1019,24 @@ static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *re
 	return decode_op_hdr(xdr, OP_DEALLOCATE);
 }
 
-static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *res,
-				 uint32_t *eof)
+static int decode_read_plus_data(struct xdr_stream *xdr,
+				 struct nfs_pgio_res *res)
 {
 	uint32_t count, recvd;
 	uint64_t offset;
 	__be32 *p;
 
 	p = xdr_inline_decode(xdr, 8 + 4);
-	if (unlikely(!p))
-		return -EIO;
+	if (!p)
+		return 1;
 
 	p = xdr_decode_hyper(p, &offset);
 	count = be32_to_cpup(p);
 	recvd = xdr_align_data(xdr, res->count, count);
 	res->count += recvd;
 
-	if (count > recvd) {
-		dprintk("NFS: server cheating in read reply: "
-				"count %u > recvd %u\n", count, recvd);
-		*eof = 0;
+	if (count > recvd)
 		return 1;
-	}
-
 	return 0;
 }
 
@@ -1052,18 +1047,16 @@ static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *re
 	__be32 *p;
 
 	p = xdr_inline_decode(xdr, 8 + 8);
-	if (unlikely(!p))
-		return -EIO;
+	if (!p)
+		return 1;
 
 	p = xdr_decode_hyper(p, &offset);
 	p = xdr_decode_hyper(p, &length);
 	recvd = xdr_expand_hole(xdr, res->count, length);
 	res->count += recvd;
 
-	if (recvd < length) {
-		*eof = 0;
+	if (recvd < length)
 		return 1;
-	}
 	return 0;
 }
 
@@ -1088,12 +1081,12 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 
 	for (i = 0; i < segments; i++) {
 		p = xdr_inline_decode(xdr, 4);
-		if (unlikely(!p))
-			return -EIO;
+		if (!p)
+			goto early_out;
 
 		type = be32_to_cpup(p++);
 		if (type == NFS4_CONTENT_DATA)
-			status = decode_read_plus_data(xdr, res, &eof);
+			status = decode_read_plus_data(xdr, res);
 		else if (type == NFS4_CONTENT_HOLE)
 			status = decode_read_plus_hole(xdr, res, &eof);
 		else
@@ -1102,12 +1095,17 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 		if (status < 0)
 			return status;
 		if (status > 0)
-			break;
+			goto early_out;
 	}
 
 out:
 	res->eof = eof;
 	return 0;
+early_out:
+	if (unlikely(!i))
+		return -EIO;
+	res->eof = 0;
+	return 0;
 }
 
 static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
-- 
2.27.0


  parent reply	other threads:[~2020-12-30 13:11 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-30 13:02 [PATCH AUTOSEL 5.10 01/31] ARM: 9014/2: Replace string mem* functions for KASan Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 02/31] rtc: sun6i: Fix memleak in sun6i_rtc_clk_init Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 03/31] module: set MODULE_STATE_GOING state when a module fails to load Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 04/31] quota: Don't overflow quota file offsets Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 05/31] rtc: pl031: fix resource leak in pl031_probe Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 06/31] powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe() Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 07/31] i3c master: fix missing destroy_workqueue() on error in i3c_master_register Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 08/31] reiserfs: add check for an invalid ih_entry_count Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 09/31] NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 10/31] f2fs: Handle casefolding with Encryption Sasha Levin
2020-12-30 18:01   ` [f2fs-dev] " Eric Biggers
2021-01-04 14:20     ` Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 11/31] f2fs: avoid race condition for shrinker count Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 12/31] f2fs: fix race of pending_pages in decompression Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 13/31] module: delay kobject uevent until after module init call Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 14/31] powerpc/64: irq replay remove decrementer overflow check Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 15/31] f2fs: fix shift-out-of-bounds in sanity_check_raw_super() Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 16/31] fs/namespace.c: WARN if mnt_count has become negative Sasha Levin
2020-12-30 13:02 ` [PATCH AUTOSEL 5.10 17/31] watchdog: rti-wdt: fix reference leak in rti_wdt_probe Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 18/31] um: random: Register random as hwrng-core device Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 19/31] um: ubd: Submit all data segments atomically Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 20/31] um: allocate a guard page to helper threads Sasha Levin
2020-12-30 14:48   ` Johannes Berg
2021-01-04 14:21     ` Sasha Levin
2020-12-30 13:03 ` Sasha Levin [this message]
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 22/31] ceph: fix inode refcount leak when ceph_fill_inode on non-I_NEW inode fails Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 23/31] drm/amd/display: updated wm table for Renoir Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 24/31] tick/sched: Remove bogus boot "safety" check Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 25/31] s390: always clear kernel stack backchain before calling functions Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 26/31] io_uring: remove racy overflow list fast checks Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 27/31] ext4: check for invalid block size early when mounting a file system Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 28/31] ALSA: pcm: Clear the full allocated memory at hw_params Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 29/31] dm verity: skip verity work if I/O error when system is shutting down Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 30/31] ext4: avoid s_mb_prefetch to be zero in individual scenarios Sasha Levin
2020-12-30 13:03 ` [PATCH AUTOSEL 5.10 31/31] device-dax: Fix range release Sasha Levin
2020-12-30 14:18 ` [PATCH AUTOSEL 5.10 01/31] ARM: 9014/2: Replace string mem* functions for KASan Ahmad Fatoum
2021-01-04 14:29   ` Sasha Levin

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