From 0dbbf0fb38d5ec5d4138d1aeaeb43d9217b9a592 Mon Sep 17 00:00:00 2001 From: Yangtao Li Date: Sat, 21 Jan 2023 00:16:55 +0800 Subject: [PATCH] f2fs: fix to avoid potential memory corruption in __update_iostat_latency() 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 Reported-by: Dan Carpenter Suggested-by: Chao Yu Suggested-by: Jaegeuk Kim Signed-off-by: Yangtao Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- 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 ed81769..9663775 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; -- 2.7.4