Linux 4.14.111

[thirdparty/kernel/stable-queue.git] / releases / 4.14.111 / bcache-fix-input-overflow-to-sequential_cutoff.patch

diff --git a/releases/4.14.111/bcache-fix-input-overflow-to-sequential_cutoff.patch b/releases/4.14.111/bcache-fix-input-overflow-to-sequential_cutoff.patch
new file mode 100644 (file)
index 0000000..6d97aaa
--- /dev/null
+++ b/releases/4.14.111/bcache-fix-input-overflow-to-sequential_cutoff.patch
@@ -0,0 +1,42 @@
+From 322c20d857dbffea47081acfd5745508689c60da Mon Sep 17 00:00:00 2001
+From: Coly Li <colyli@suse.de>
+Date: Sat, 9 Feb 2019 12:53:01 +0800
+Subject: bcache: fix input overflow to sequential_cutoff
+
+[ Upstream commit 8c27a3953e92eb0b22dbb03d599f543a05f9574e ]
+
+People may set sequential_cutoff of a cached device via sysfs file,
+but current code does not check input value overflow. E.g. if value
+4294967295 (UINT_MAX) is written to file sequential_cutoff, its value
+is 4GB, but if 4294967296 (UINT_MAX + 1) is written into, its value
+will be 0. This is an unexpected behavior.
+
+This patch replaces d_strtoi_h() by sysfs_strtoul_clamp() to convert
+input string to unsigned integer value, and limit its range in
+[0, UINT_MAX]. Then the input overflow can be fixed.
+
+Signed-off-by: Coly Li <colyli@suse.de>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/md/bcache/sysfs.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
+index 43ff7fbcbc7c..def9c3478b89 100644
+--- a/drivers/md/bcache/sysfs.c
++++ b/drivers/md/bcache/sysfs.c
+@@ -217,7 +217,9 @@ STORE(__cached_dev)
+       d_strtoul(writeback_rate_d_term);
+       d_strtoul_nonzero(writeback_rate_p_term_inverse);
+ 
+-      d_strtoi_h(sequential_cutoff);
++      sysfs_strtoul_clamp(sequential_cutoff,
++                          dc->sequential_cutoff,
++                          0, UINT_MAX);
+       d_strtoi_h(readahead);
+ 
+       if (attr == &sysfs_clear_stats)
+-- 
+2.19.1
+