CVE-2023-53214

In the Linux kernel, the following vulnerability has been resolved:

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.

This vulnerability does not affect supported Red Hat Enterprise Linux releases because the vulnerable code within the F2FS subsystem is not present in Red Hat kernels. The flaw stems from improper indexing in I/O statistics latency handling introduced in upstream Linux kernel 5.15, which was never backported to Red Hat Enterprise Linux. As a result, default installations and enterprise deployments are not exposed to this issue.