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| author | Bart Van Assche <bart.vanassche@wdc.com> | 2017-08-30 11:42:09 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-09-01 13:56:39 -0600 |
| commit | 2f79136ba2df07ce7563158f7948c4ce770f8132 (patch) | |
| tree | 2a68b34d5162b00bf65a3fcb8f32d61eaa31623a /block | |
| parent | dfb79af5469a028e23ba2592a577d9b6f8a5651f (diff) | |
| download | linux-2f79136ba2df07ce7563158f7948c4ce770f8132.tar.bz2 | |
bfq: Check kstrtoul() return value
Make sysfs writes fail for invalid numbers instead of storing
uninitialized data copied from the stack. This patch removes
all uninitialized_var() occurrences from the BFQ source code.
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bfq-iosched.c | 52 |
1 files changed, 37 insertions, 15 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 856f4199a470..0f286cd5da95 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4802,13 +4802,15 @@ static ssize_t bfq_var_show(unsigned int var, char *page) return sprintf(page, "%u\n", var); } -static void bfq_var_store(unsigned long *var, const char *page) +static int bfq_var_store(unsigned long *var, const char *page) { unsigned long new_val; int ret = kstrtoul(page, 10, &new_val); - if (ret == 0) - *var = new_val; + if (ret) + return ret; + *var = new_val; + return 0; } #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ @@ -4849,8 +4851,12 @@ static ssize_t \ __FUNC(struct elevator_queue *e, const char *page, size_t count) \ { \ struct bfq_data *bfqd = e->elevator_data; \ - unsigned long uninitialized_var(__data); \ - bfq_var_store(&__data, (page)); \ + unsigned long __data; \ + int ret; \ + \ + ret = bfq_var_store(&__data, (page)); \ + if (ret) \ + return ret; \ if (__data < (MIN)) \ __data = (MIN); \ else if (__data > (MAX)) \ @@ -4877,8 +4883,12 @@ STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2); static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)\ { \ struct bfq_data *bfqd = e->elevator_data; \ - unsigned long uninitialized_var(__data); \ - bfq_var_store(&__data, (page)); \ + unsigned long __data; \ + int ret; \ + \ + ret = bfq_var_store(&__data, (page)); \ + if (ret) \ + return ret; \ if (__data < (MIN)) \ __data = (MIN); \ else if (__data > (MAX)) \ @@ -4894,9 +4904,12 @@ static ssize_t bfq_max_budget_store(struct elevator_queue *e, const char *page, size_t count) { struct bfq_data *bfqd = e->elevator_data; - unsigned long uninitialized_var(__data); + unsigned long __data; + int ret; - bfq_var_store(&__data, (page)); + ret = bfq_var_store(&__data, (page)); + if (ret) + return ret; if (__data == 0) bfqd->bfq_max_budget = bfq_calc_max_budget(bfqd); @@ -4919,9 +4932,12 @@ static ssize_t bfq_timeout_sync_store(struct elevator_queue *e, const char *page, size_t count) { struct bfq_data *bfqd = e->elevator_data; - unsigned long uninitialized_var(__data); + unsigned long __data; + int ret; - bfq_var_store(&__data, (page)); + ret = bfq_var_store(&__data, (page)); + if (ret) + return ret; if (__data < 1) __data = 1; @@ -4939,9 +4955,12 @@ static ssize_t bfq_strict_guarantees_store(struct elevator_queue *e, const char *page, size_t count) { struct bfq_data *bfqd = e->elevator_data; - unsigned long uninitialized_var(__data); + unsigned long __data; + int ret; - bfq_var_store(&__data, (page)); + ret = bfq_var_store(&__data, (page)); + if (ret) + return ret; if (__data > 1) __data = 1; @@ -4958,9 +4977,12 @@ static ssize_t bfq_low_latency_store(struct elevator_queue *e, const char *page, size_t count) { struct bfq_data *bfqd = e->elevator_data; - unsigned long uninitialized_var(__data); + unsigned long __data; + int ret; - bfq_var_store(&__data, (page)); + ret = bfq_var_store(&__data, (page)); + if (ret) + return ret; if (__data > 1) __data = 1; |