Add iotype sanity check to avoid potential memory corruption.
This is to fix the compile error below:
fs/f2fs/iostat.c:231 __update_iostat_latency() error: buffer overflow
'io_lat->peak_lat[type]' 3 <= 3
vim +228 fs/f2fs/iostat.c
211 static inline void __update_iostat_latency(struct bio_iostat_ctx
*iostat_ctx,
212 enum iostat_lat_type type)
213 {
214 unsigned long ts_diff;
215 unsigned int page_type = iostat_ctx->type;
216 struct f2fs_sb_info *sbi = iostat_ctx->sbi;
217 struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
218 unsigned long flags;
219
220 if (!sbi->iostat_enable)
221 return;
222
223 ts_diff = jiffies - iostat_ctx->submit_ts;
224 if (page_type >= META_FLUSH)
^^^^^^^^^^
225 page_type = META;
226
227 spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
@228 io_lat->sum_lat[type][page_type] += ts_diff;
^^^^^^^^^
Mixup between META_FLUSH and NR_PAGE_TYPE leads to memory corruption.
Fixes: a4b6817625e7 ("f2fs: introduce periodic iostat io latency traces")
Reported-by: kernel test robot <l...@intel.com>
Reported-by: Dan Carpenter <erro...@gmail.com>
Suggested-by: Chao Yu <c...@kernel.org>
Suggested-by: Jaegeuk Kim <jaeg...@kernel.org>
Signed-off-by: Yangtao Li <frank...@vivo.com>
---
v3:
-convert to warn
fs/f2fs/iostat.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
index ed8176939aa5..96637756eae8 100644
--- a/fs/f2fs/iostat.c
+++ b/fs/f2fs/iostat.c
@@ -223,8 +223,12 @@ static inline void __update_iostat_latency(struct
bio_iostat_ctx *iostat_ctx,
return;
ts_diff = jiffies - iostat_ctx->submit_ts;
- if (iotype >= META_FLUSH)
+ if (iotype == META_FLUSH) {
iotype = META;
+ } else if (iotype >= NR_PAGE_TYPE) {
+ f2fs_warn(sbi, "%s: %d over NR_PAGE_TYPE", __func__, iotype);
+ return;
+ }
if (rw == 0) {
idx = READ_IO;
--
2.25.1
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