From b2bc7c44ed1779fc9eaab9a186db0f0d01439622 Mon Sep 17 00:00:00 2001 From: Jiasheng Jiang Date: Sat, 17 Jan 2026 16:50:24 +0000 Subject: [PATCH] fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot 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 Signed-off-by: Konstantin Komarov --- fs/ntfs3/fslog.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c index 4ea94d53a819..10863c83c315 100644 --- a/fs/ntfs3/fslog.c +++ b/fs/ntfs3/fslog.c @@ -3431,6 +3431,9 @@ move_data: 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))); -- 2.47.3