From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Johannes Thumshirn <jth@kernel.org>,
David Sterba <dsterba@suse.com>, Sasha Levin <sashal@kernel.org>,
linux-btrfs@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 144/186] btrfs: fix possible NULL-pointer dereference in integrity checks
Date: Fri, 14 Feb 2020 11:16:33 -0500 [thread overview]
Message-ID: <20200214161715.18113-144-sashal@kernel.org> (raw)
In-Reply-To: <20200214161715.18113-1-sashal@kernel.org>
From: Johannes Thumshirn <jth@kernel.org>
[ Upstream commit 3dbd351df42109902fbcebf27104149226a4fcd9 ]
A user reports a possible NULL-pointer dereference in
btrfsic_process_superblock(). We are assigning state->fs_info to a local
fs_info variable and afterwards checking for the presence of state.
While we would BUG_ON() a NULL state anyways, we can also just remove
the local fs_info copy, as fs_info is only used once as the first
argument for btrfs_num_copies(). There we can just pass in
state->fs_info as well.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205003
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/check-integrity.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 7d5a9b51f0d7a..4be07cf31d74c 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -642,7 +642,6 @@ static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev,
static int btrfsic_process_superblock(struct btrfsic_state *state,
struct btrfs_fs_devices *fs_devices)
{
- struct btrfs_fs_info *fs_info = state->fs_info;
struct btrfs_super_block *selected_super;
struct list_head *dev_head = &fs_devices->devices;
struct btrfs_device *device;
@@ -713,7 +712,7 @@ static int btrfsic_process_superblock(struct btrfsic_state *state,
break;
}
- num_copies = btrfs_num_copies(fs_info, next_bytenr,
+ num_copies = btrfs_num_copies(state->fs_info, next_bytenr,
state->metablock_size);
if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES)
pr_info("num_copies(log_bytenr=%llu) = %d\n",
--
2.20.1
next parent reply other threads:[~2020-02-14 16:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200214161715.18113-1-sashal@kernel.org>
2020-02-14 16:16 ` Sasha Levin [this message]
2020-02-14 16:16 ` [PATCH AUTOSEL 4.14 145/186] btrfs: safely advance counter when looking up bio csums Sasha Levin
2020-02-14 16:16 ` [PATCH AUTOSEL 4.14 146/186] btrfs: device stats, log when stats are zeroed Sasha Levin
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