From: Jiasheng Jiang <jiashengjiangcool@gmail.com> stable inclusion from stable-v5.15.202 commit 36c03f7f177b34d51f1cf1d2304b1074607bf4b0 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15173 CVE: CVE-2026-45935 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/... -------------------------------- [ Upstream commit b2bc7c44ed1779fc9eaab9a186db0f0d01439622 ] In the 'DeleteIndexEntryRoot' case of the 'do_action' function, the entry size ('esize') is retrieved from the log record without adequate bounds checking. Specifically, the code calculates the end of the entry ('e2') using: e2 = Add2Ptr(e1, esize); It then calculates the size for memmove using 'PtrOffset(e2, ...)', which subtracts the end pointer from the buffer limit. If 'esize' is maliciously large, 'e2' exceeds the used buffer size. This results in a negative offset which, when cast to size_t for memmove, interprets as a massive unsigned integer, leading to a heap buffer overflow. This commit adds a check to ensure that the entry size ('esize') strictly fits within the remaining used space of the index header before performing memory operations. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zizhi Wo <wozizhi@huawei.com> --- fs/ntfs3/fslog.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c index d1f48ffe846e..ef4e7dbc35cf 100644 --- a/fs/ntfs3/fslog.c +++ b/fs/ntfs3/fslog.c @@ -3435,10 +3435,13 @@ static int do_action(struct ntfs_log *log, struct OPEN_ATTR_ENRTY *oe, goto dirty_vol; } e1 = Add2Ptr(attr, le16_to_cpu(lrh->attr_off)); esize = le16_to_cpu(e1->size); + if (PtrOffset(e1, Add2Ptr(hdr, used)) < esize) + goto dirty_vol; + e2 = Add2Ptr(e1, esize); memmove(e1, e2, PtrOffset(e2, Add2Ptr(hdr, used))); le32_sub_cpu(&attr->res.data_size, esize); -- 2.52.0