ends, resulting in an out-of-bounds read of 1 byte from the p_cstring stack memory. Therefore, to prevent this and properly determine whether nls has been lost, it should be modified to check if "i" and len are equal, rather than dereferencing p_cstring. Cc: Reported-by: syzbot+98cc76a76de46b3714d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=98cc76a76de46b3714d4 Fixes: 370e812b3ec1 ("exfat: add nls operations") Signed-off-by: Jeongjun Park --- fs/exfat/nls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c index 8243d94ceaf4..de06abe426d7 100644 --- a/fs/exfat/nls.c +++ b/fs/exfat/nls.c @@ -616,7 +616,7 @@ static int exfat_nls_to_ucs2(struct super_block *sb, unilen++; } - if (p_cstring[i] != '\0') + if (i != len) lossy |= NLS_NAME_OVERLEN; *uniname = '\0'; --[PATCH v2] exfat: fix out-of-bounds in exfat_nls_to_ucs2()Jeongjun Park undefinedNamjae Jeon , Sungjong Seo undefined undefined undefined undefined undefined undefined undefined undefined undefined†'ƒ‹F