mainline inclusion from mainline-5.1-rc1 commit b15008403b59955c9fa0c8b55cadd6dae991a4e9 category: backport
c->error_limit is in type unsigned int, it is set via cache set sysfs file io_error_limit. Inside the bcache code, input string is converted by strtoul_or_return() and set the converted value to c->error_limit.
Because the converted value is unsigned long, and c->error_limit is unsigned int, if the input is large enought, overflow will happen to c->error_limit.
This patch uses sysfs_strtoul_clamp() to convert input string, and set the range in [0, UINT_MAX] to avoid the potential overflow.
Signed-off-by: Coly Li colyli@suse.de Signed-off-by: Jens Axboe axboe@kernel.dk --- drivers/md/bcache/sysfs.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index 48234481cd50..3ae271f95ffe 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -806,8 +806,7 @@ STORE(__bch_cache_set) c->on_error = v; }
- if (attr == &sysfs_io_error_limit) - c->error_limit = strtoul_or_return(buf); + sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
/* See count_io_errors() for why 88 */ if (attr == &sysfs_io_error_halflife) {