stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Siddh Raman Pant <code@siddh.me>,
	syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com,
	Gao Xiang <hsiangkao@linux.alibaba.com>,
	Chao Yu <chao@kernel.org>, Sasha Levin <sashal@kernel.org>,
	xiang@kernel.org, linux-erofs@lists.ozlabs.org
Subject: [PATCH AUTOSEL 6.1 07/35] erofs/zmap.c: Fix incorrect offset calculation
Date: Tue, 24 Jan 2023 08:41:03 -0500	[thread overview]
Message-ID: <20230124134131.637036-7-sashal@kernel.org> (raw)
In-Reply-To: <20230124134131.637036-1-sashal@kernel.org>

From: Siddh Raman Pant <code@siddh.me>

[ Upstream commit 6acd87d50998ef0afafc441613aeaf5a8f5c9eff ]

Effective offset to add to length was being incorrectly calculated,
which resulted in iomap->length being set to 0, triggering a WARN_ON
in iomap_iter_done().

Fix that, and describe it in comments.

This was reported as a crash by syzbot under an issue about a warning
encountered in iomap_iter_done(), but unrelated to erofs.

C reproducer: https://syzkaller.appspot.com/text?tag=ReproC&x=1037a6b2880000
Kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=e2021a61197ebe02
Dashboard link: https://syzkaller.appspot.com/bug?extid=a8e049cd3abd342936b6

Reported-by: syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com
Suggested-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Siddh Raman Pant <code@siddh.me>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20221209102151.311049-1-code@siddh.me
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/erofs/zmap.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index e6d5d7a18fb0..39cc014dba40 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -793,12 +793,16 @@ static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
 		iomap->type = IOMAP_HOLE;
 		iomap->addr = IOMAP_NULL_ADDR;
 		/*
-		 * No strict rule how to describe extents for post EOF, yet
-		 * we need do like below. Otherwise, iomap itself will get
+		 * No strict rule on how to describe extents for post EOF, yet
+		 * we need to do like below. Otherwise, iomap itself will get
 		 * into an endless loop on post EOF.
+		 *
+		 * Calculate the effective offset by subtracting extent start
+		 * (map.m_la) from the requested offset, and add it to length.
+		 * (NB: offset >= map.m_la always)
 		 */
 		if (iomap->offset >= inode->i_size)
-			iomap->length = length + map.m_la - offset;
+			iomap->length = length + offset - map.m_la;
 	}
 	iomap->flags = 0;
 	return 0;
-- 
2.39.0


  parent reply	other threads:[~2023-01-24 13:42 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-24 13:40 [PATCH AUTOSEL 6.1 01/35] ARM: dts: imx: Fix pca9547 i2c-mux node name Sasha Levin
2023-01-24 13:40 ` [PATCH AUTOSEL 6.1 02/35] ARM: dts: vf610: Fix pca9548 i2c-mux node names Sasha Levin
2023-01-24 13:40 ` [PATCH AUTOSEL 6.1 03/35] arm64: dts: freescale: Fix pca954x " Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 04/35] arm64: dts: imx8mq-thor96: fix no-mmc property for SDHCI Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 05/35] firmware: arm_scmi: Clear stale xfer->hdr.status Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 06/35] bpf: Skip task with pid=1 in send_signal_common() Sasha Levin
2023-01-24 13:41 ` Sasha Levin [this message]
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 08/35] mac80211: Fix MLO address translation for multiple bss case Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 09/35] arm64: dts: msm8994-angler: fix the memory map Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 10/35] ARM: omap1: fix building gpio15xx Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 11/35] init/Kconfig: fix LOCALVERSION_AUTO help text Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 12/35] kselftest: Fix error message for unconfigured LLVM builds Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 13/35] erofs: clean up parsing of fscache related options Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 14/35] btrfs: factor out scratching of one regular super block Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 15/35] btrfs: stop using write_one_page in btrfs_scratch_superblock Sasha Levin
2023-01-24 16:57   ` David Sterba
2023-02-01 15:21     ` Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 16/35] blk-cgroup: fix missing pd_online_fn() while activating policy Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 17/35] LoongArch: Get frame info in unwind_start() when regs is not available Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 18/35] ACPI: video: Add backlight=native DMI quirk for Acer Aspire 4810T Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 19/35] block: fix hctx checks for batch allocation Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 20/35] s390: workaround invalid gcc-11 out of bounds read warning Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 21/35] HID: uclogic: Add support for XP-PEN Deco 01 V2 Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 22/35] HID: playstation: sanity check DualSense calibration data Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 23/35] dmaengine: imx-sdma: Fix a possible memory leak in sdma_transfer_init Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 24/35] gpiolib: acpi: Allow ignoring wake capability on pins that aren't in _AEI Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 25/35] cifs: fix return of uninitialized rc in dfs_cache_update_tgthint() Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 26/35] nvme-apple: only reset the controller when RTKit is running Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 27/35] octeontx2-af: recover CPT engine when it gets fault Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 28/35] octeontx2-af: add mbox for CPT LF reset Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 29/35] octeontx2-af: modify FLR sequence for CPT Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 30/35] octeontx2-af: optimize cpt pf identification Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 31/35] octeontx2-af: restore rxc conf after teardown sequence Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 32/35] octeontx2-af: update cpt lf alloc mailbox Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 33/35] octeontx2-af: add mbox to return CPT_AF_FLT_INT info Sasha Levin
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 34/35] prlimit: do_prlimit needs to have a speculation check Sasha Levin
2023-01-24 15:28   ` Greg Kroah-Hartman
2023-01-24 13:41 ` [PATCH AUTOSEL 6.1 35/35] ext4: deal with legacy signed xattr name hash values Sasha Levin
2023-01-24 16:50   ` Linus Torvalds
2023-01-24 17:23     ` Linus Torvalds
2023-01-25 16:01       ` Theodore Ts'o
2023-01-26 14:12         ` Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230124134131.637036-7-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=chao@kernel.org \
    --cc=code@siddh.me \
    --cc=hsiangkao@linux.alibaba.com \
    --cc=linux-erofs@lists.ozlabs.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com \
    --cc=xiang@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).