Fix possible NULL (sc->dfs_detector) pointer dereference.
Detected by Smatch:
drivers/net/wireless/ath/ath9k/dfs_debug.c:67 read_file_dfs()
error: we previously assumed 'sc->dfs_detector' could be null (see line 47)
Signed-off-by: Janusz Dziedzic <janusz.dziedzic@xxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/dfs_debug.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/dfs_debug.c b/drivers/net/wireless/ath/ath9k/dfs_debug.c
index 36cd82f..df00061 100644
--- a/drivers/net/wireless/ath/ath9k/dfs_debug.c
+++ b/drivers/net/wireless/ath/ath9k/dfs_debug.c
@@ -44,14 +44,20 @@ static ssize_t read_file_dfs(struct file *file, char __user *user_buf,
if (buf == NULL)
return -ENOMEM;
- if (sc->dfs_detector)
- dfs_pool_stats = sc->dfs_detector->get_stats(sc->dfs_detector);
-
len += snprintf(buf + len, size - len, "DFS support for "
"macVersion = 0x%x, macRev = 0x%x: %s\n",
hw_ver->macVersion, hw_ver->macRev,
(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_DFS) ?
"enabled" : "disabled");
+
+ if (!sc->dfs_detector) {
+ len += snprintf(buf + len, size - len,
+ "DFS detector not enabled\n");
+ goto exit;
+ }
+
+ dfs_pool_stats = sc->dfs_detector->get_stats(sc->dfs_detector);
+
len += snprintf(buf + len, size - len, "Pulse detector statistics:\n");
ATH9K_DFS_STAT("pulse events reported ", pulses_total);
ATH9K_DFS_STAT("invalid pulse events ", pulses_no_dfs);
@@ -75,6 +81,7 @@ static ssize_t read_file_dfs(struct file *file, char __user *user_buf,
ATH9K_DFS_POOL_STAT("Seqs. alloc error ", pseq_alloc_error);
ATH9K_DFS_POOL_STAT("Seqs. in use ", pseq_used);
+exit:
if (len > size)
len = size;
--
1.7.9.5
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