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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Jeff Layton <jlayton@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.9 06/12] iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT
Date: Thu, 11 Aug 2022 12:11:32 -0400	[thread overview]
Message-ID: <20220811161144.1543598-6-sashal@kernel.org> (raw)
In-Reply-To: <20220811161144.1543598-1-sashal@kernel.org>

From: Al Viro <viro@zeniv.linux.org.uk>

[ Upstream commit 7392ed1734c319150b5ddec3f192a6405728e8d0 ]

All callers can and should handle iov_iter_get_pages() returning
fewer pages than requested.  All in-kernel ones do.  And it makes
the arithmetical overflow analysis much simpler...

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 lib/iov_iter.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index e01bb1c51d87..c4b9896422ae 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -951,6 +951,8 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
 
 	if (!maxsize)
 		return 0;
+	if (maxsize > MAX_RW_COUNT)
+		maxsize = MAX_RW_COUNT;
 
 	if (unlikely(i->type & ITER_PIPE))
 		return pipe_get_pages(i, pages, maxsize, maxpages, start);
@@ -1031,6 +1033,8 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 
 	if (!maxsize)
 		return 0;
+	if (maxsize > MAX_RW_COUNT)
+		maxsize = MAX_RW_COUNT;
 
 	if (unlikely(i->type & ITER_PIPE))
 		return pipe_get_pages_alloc(i, pages, maxsize, start);
-- 
2.35.1


  parent reply	other threads:[~2022-08-11 16:38 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-11 16:11 [PATCH AUTOSEL 4.9 01/12] drm/r128: Fix undefined behavior due to shift overflowing the constant Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 02/12] drm/radeon: Initialize fences array entries in radeon_sa_bo_next_hole Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 03/12] media: airspy: respect the DMA coherency rules Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 04/12] media: pvrusb2: fix memory leak in pvr_probe Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 05/12] mlxsw: cmd: Increase 'config_profile.flood_mode' length Sasha Levin
2022-08-13 13:43   ` Pavel Machek
2022-08-11 16:11 ` Sasha Levin [this message]
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 07/12] crypto: vmx - Fix warning on p8_ghash_alg Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 08/12] can: sja1000: Add Quirk for RZ/N1 SJA1000 CAN controller Sasha Levin
2022-08-13 13:44   ` Pavel Machek
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 09/12] net/cdc_ncm: Increase NTB max RX/TX values to 64kb Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 10/12] wifi: rtl8xxxu: Fix the error handling of the probe function Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 11/12] d_add_ci(): make sure we don't miss d_lookup_done() Sasha Levin
2022-08-11 16:11 ` [PATCH AUTOSEL 4.9 12/12] fs/dcache: Disable preemption on i_dir_seq write side on PREEMPT_RT Sasha Levin

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