From: Shayne Chen shayne.chen@mediatek.com
[ Upstream commit 6020d534fa012b80c6d13811dc4d2dfedca2e403 ]
This fixes strlen mismatch problems happening in some .write callbacks of debugfs.
When trying to configure airtime_flags in debugfs, an error appeared: ash: write error: Invalid argument
The error is returned from kstrtou16() since a wrong length makes it miss the real end of input string. To fix this, use count as the string length, and set proper end of string for a char buffer.
The debug print is shown - airtime_flags_write: count = 2, len = 8, where the actual length is 2, but "len = strlen(buf)" gets 8.
Also cleanup the other similar cases for the sake of consistency.
Signed-off-by: Sujuan Chen sujuan.chen@mediatek.com Signed-off-by: Ryder Lee ryder.lee@mediatek.com Signed-off-by: Shayne Chen shayne.chen@mediatek.com Link: https://lore.kernel.org/r/20210112032028.7482-1-shayne.chen@mediatek.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/debugfs.c | 44 +++++++++++++++++++----------------------- 1 file changed, 20 insertions(+), 24 deletions(-)
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c index 90470392fdaa7..de5cd3818690c 100644 --- a/net/mac80211/debugfs.c +++ b/net/mac80211/debugfs.c @@ -120,18 +120,17 @@ static ssize_t aqm_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[100]; - size_t len;
- if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL;
if (copy_from_user(buf, user_buf, count)) return -EFAULT;
- buf[sizeof(buf) - 1] = '\0'; - len = strlen(buf); - if (len > 0 && buf[len-1] == '\n') - buf[len-1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0';
if (sscanf(buf, "fq_limit %u", &local->fq.limit) == 1) return count; @@ -177,18 +176,17 @@ static ssize_t airtime_flags_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[16]; - size_t len;
- if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL;
if (copy_from_user(buf, user_buf, count)) return -EFAULT;
- buf[sizeof(buf) - 1] = 0; - len = strlen(buf); - if (len > 0 && buf[len - 1] == '\n') - buf[len - 1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0';
if (kstrtou16(buf, 0, &local->airtime_flags)) return -EINVAL; @@ -237,20 +235,19 @@ static ssize_t aql_txq_limit_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[100]; - size_t len; u32 ac, q_limit_low, q_limit_high, q_limit_low_old, q_limit_high_old; struct sta_info *sta;
- if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL;
if (copy_from_user(buf, user_buf, count)) return -EFAULT;
- buf[sizeof(buf) - 1] = 0; - len = strlen(buf); - if (len > 0 && buf[len - 1] == '\n') - buf[len - 1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0';
if (sscanf(buf, "%u %u %u", &ac, &q_limit_low, &q_limit_high) != 3) return -EINVAL; @@ -306,18 +303,17 @@ static ssize_t force_tx_status_write(struct file *file, { struct ieee80211_local *local = file->private_data; char buf[3]; - size_t len;
- if (count > sizeof(buf)) + if (count >= sizeof(buf)) return -EINVAL;
if (copy_from_user(buf, user_buf, count)) return -EFAULT;
- buf[sizeof(buf) - 1] = '\0'; - len = strlen(buf); - if (len > 0 && buf[len - 1] == '\n') - buf[len - 1] = 0; + if (count && buf[count - 1] == '\n') + buf[count - 1] = '\0'; + else + buf[count] = '\0';
if (buf[0] == '0' && buf[1] == '\0') local->force_tx_status = 0;