From: Shigeru Yoshida <syoshida@redhat.com> stable inclusion from stable-v5.15.45 commit 4b51f27d4448c84957bce190292f75d4896d56b3 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP6TI CVE: CVE-2022-49553 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- syzbot reported UBSAN error as below: [ 76.901829][ T6677] ================================================================================ [ 76.903908][ T6677] UBSAN: shift-out-of-bounds in fs/ntfs3/super.c:675:13 [ 76.905363][ T6677] shift exponent -247 is negative This patch avoid this error. Link: https://syzkaller.appspot.com/bug?id=b0299c09a14aababf0f1c862dd4ebc8ab9eb017... Fixes: a3b774342fa7 (fs/ntfs3: validate BOOT sectors_per_clusters) Cc: Author: Randy Dunlap <rdunlap@infradead.org> Reported-by: syzbot+35b87c668935bb55e666@syzkaller.appspotmail.com Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Signed-off-by: Zizhi Wo <wozizhi@huawei.com> --- fs/ntfs3/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c index 245deb0736ce..e3e93afa07ed 100644 --- a/fs/ntfs3/super.c +++ b/fs/ntfs3/super.c @@ -671,7 +671,7 @@ static u32 true_sectors_per_clst(const struct NTFS_BOOT *boot) if (boot->sectors_per_clusters <= 0x80) return boot->sectors_per_clusters; if (boot->sectors_per_clusters >= 0xf4) /* limit shift to 2MB max */ - return 1U << (0 - boot->sectors_per_clusters); + return 1U << -(s8)boot->sectors_per_clusters; return -EINVAL; } -- 2.39.2