From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AB1A3AF66E; Wed, 30 Sep 2026 17:54:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790885; cv=none; b=VcjvuT/cpidsqg5WCX02pn2Wgx+7N3vTp8FXYgXxPdZAJ40rDw2tH60Uolyj+vobqvUN7+t2Nn8s9mHtR+ds7c/Rdj7tOBfRm20tS2FVFtwmsVithRF6UTVCNMVCHo+ucgNTf+WZqRMSJ9kplmk/ynhBqst8KzA8vKH0VlsnKnk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790885; c=relaxed/simple; bh=PwFxA6+bKvwy+3r81wG3fPHtJNZcXb7lKkx/F08QLP0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h9ZRiKuHXsQWDs5HfaKZL+dD/FoTSvVE74o++CuNPh/jfWAQ3H+O1uFjqAaznWTEr0pKsioRNl+fz5+KHleOWl+xsFl4PadgKRZwWBqsR4PjEjopwd/W5FfjcoeBsxNXaLL024KSg2ws0ilS5Ysbfo36ZWWc+fg7x9vhZVYEsM4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GE95jn0i; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GE95jn0i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FB331F000FF; Wed, 30 Sep 2026 17:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790790883; bh=laXxHiybF8sNjtnpipfbRF2mS5OiBKWU0DPndZ65hHk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GE95jn0iopy+EkcCRtdZqqJUpa48OB8yRxfLxSM+q5JmMMF6R9MDNaJTYOOTyHyTJ 3qSpYFb6Z1GOni6Ljafu/7jxLJIVEIlSFcBcNSNrerk9mrv5VetRHBn5nN49bi1OpK iUi6OMXETEi8KVuU+p1EkcYdVJtspvaIIsEPQJtk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, ZhengYuan Huang , Konstantin Komarov , Sasha Levin Subject: [PATCH 5.15 107/752] fs/ntfs3: validate index entry key bounds Date: Wed, 30 Sep 2026 17:19:37 +0200 Message-ID: <20260930152400.483797380@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: ZhengYuan Huang [ Upstream commit 98d6e5d9dc1d34dcffc61549617581a5fe1ef807 ] [BUG] A malformed NTFS directory index entry can advertise a key_size larger than the bytes actually present in its NTFS_DE payload. Directory lookup then passes that malformed key to cmp_fnames(), which can read past the end of the kmalloc'ed index buffer. BUG: KASAN: slab-out-of-bounds in fname_full_size fs/ntfs3/ntfs.h:590 [inline] BUG: KASAN: slab-out-of-bounds in cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46 Read of size 1 at addr ffff88801c313018 by task syz.6.3365/9279 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xd1/0x650 mm/kasan/report.c:482 kasan_report+0xfb/0x140 mm/kasan/report.c:595 __asan_report_load1_noabort+0x14/0x30 mm/kasan/report_generic.c:378 fname_full_size fs/ntfs3/ntfs.h:590 [inline] cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46 hdr_find_e.isra.0+0x3ed/0x670 fs/ntfs3/index.c:762 indx_find+0x4b5/0x900 fs/ntfs3/index.c:1186 dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254 ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85 __lookup_slow+0x241/0x450 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x31c/0x570 fs/namei.c:2151 link_path_walk+0x592/0xd60 fs/namei.c:2519 path_lookupat+0x138/0x660 fs/namei.c:2675 filename_lookup+0x1f3/0x560 fs/namei.c:2705 filename_setxattr+0xad/0x1c0 fs/xattr.c:660 path_setxattrat+0x1d8/0x280 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750 ... Allocated by task 9279: kasan_save_stack+0x39/0x70 mm/kasan/common.c:56 kasan_save_track+0x14/0x40 mm/kasan/common.c:77 kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] indx_read+0x41d/0xad0 fs/ntfs3/index.c:1059 indx_find+0x447/0x900 fs/ntfs3/index.c:1179 dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254 ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85 __lookup_slow+0x241/0x450 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x31c/0x570 fs/namei.c:2151 link_path_walk+0x592/0xd60 fs/namei.c:2519 path_lookupat+0x138/0x660 fs/namei.c:2675 filename_lookup+0x1f3/0x560 fs/namei.c:2705 filename_setxattr+0xad/0x1c0 fs/xattr.c:660 path_setxattrat+0x1d8/0x280 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750 ... [CAUSE] The index-header validators only validated INDEX_HDR-level geometry. They did not walk each NTFS_DE to verify entry alignment, subnode layout, or that key_size fit inside the entry payload. They also allowed a last sentinel entry to carry a non-zero key_size. [FIX] Walk every NTFS_DE in ntfs3's index-header validators and reject entries with invalid layout, mismatched subnode state, oversized key_size, or non-zero sentinel keys before lookup or log replay can consume them. Signed-off-by: ZhengYuan Huang Signed-off-by: Konstantin Komarov Signed-off-by: Sasha Levin --- fs/ntfs3/fslog.c | 26 ++++++++++++++++++++------ fs/ntfs3/index.c | 37 ++++++++++++++++++++++++++++++++++++- 2 files changed, 56 insertions(+), 7 deletions(-) diff --git a/fs/ntfs3/fslog.c b/fs/ntfs3/fslog.c index f9a7e17031b04..d50cda25cabc6 100644 --- a/fs/ntfs3/fslog.c +++ b/fs/ntfs3/fslog.c @@ -2645,11 +2645,12 @@ static int read_next_log_rec(struct ntfs_log *log, struct lcb *lcb, u64 *lsn) bool check_index_header(const struct INDEX_HDR *hdr, size_t bytes) { + const bool has_subnode = hdr_has_subnode(hdr); __le16 mask; u32 min_de, de_off, used, total; const struct NTFS_DE *e; - if (hdr_has_subnode(hdr)) { + if (has_subnode) { min_de = sizeof(struct NTFS_DE) + sizeof(u64); mask = NTFS_IE_HAS_SUBNODES; } else { @@ -2666,20 +2667,33 @@ bool check_index_header(const struct INDEX_HDR *hdr, size_t bytes) return false; } - e = Add2Ptr(hdr, de_off); + e = (const struct NTFS_DE *)((const u8 *)hdr + de_off); for (;;) { u16 esize = le16_to_cpu(e->size); - struct NTFS_DE *next = Add2Ptr(e, esize); + u16 key_size = le16_to_cpu(e->key_size); + u16 data_size; - if (esize < min_de || PtrOffset(hdr, next) > used || + if (!IS_ALIGNED(esize, 8) || esize < min_de || (e->flags & NTFS_IE_HAS_SUBNODES) != mask) { return false; } - if (de_is_last(e)) + if (size_add(de_off, esize) > used) + return false; + + if (de_is_last(e)) { + if (key_size) + return false; + break; + } + + data_size = esize - min_de; + if (key_size > data_size) + return false; - e = next; + de_off += esize; + e = (const struct NTFS_DE *)((const u8 *)hdr + de_off); } return true; diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c index b3f57535fe0b1..73ee8fb4b535e 100644 --- a/fs/ntfs3/index.c +++ b/fs/ntfs3/index.c @@ -612,16 +612,51 @@ static const struct NTFS_DE *hdr_insert_head(struct INDEX_HDR *hdr, */ static bool index_hdr_check(const struct INDEX_HDR *hdr, u32 bytes) { + const bool has_subnode = hdr_has_subnode(hdr); + const u16 min_size = sizeof(struct NTFS_DE) + + (has_subnode ? sizeof(u64) : 0); u32 end = le32_to_cpu(hdr->used); u32 tot = le32_to_cpu(hdr->total); u32 off = le32_to_cpu(hdr->de_off); + const struct NTFS_DE *e; if (!IS_ALIGNED(off, 8) || tot > bytes || end > tot || - size_add(off, sizeof(struct NTFS_DE)) > end) { + size_add(off, min_size) > end) { /* incorrect index buffer. */ return false; } + /* Ensure every key stays inside its entry before lookup walks it. */ + e = (const struct NTFS_DE *)((const u8 *)hdr + off); + for (;;) { + u16 e_size = le16_to_cpu(e->size); + u16 key_size = le16_to_cpu(e->key_size); + u16 data_size; + + if (!IS_ALIGNED(e_size, 8) || e_size < min_size || + de_has_vcn(e) != has_subnode) { + /* incorrect index entry. */ + return false; + } + + if (size_add(off, e_size) > end) + return false; + + if (de_is_last(e)) { + if (key_size) + return false; + + break; + } + + data_size = e_size - min_size; + if (key_size > data_size) + return false; + + off += e_size; + e = (const struct NTFS_DE *)((const u8 *)hdr + off); + } + return true; } -- 2.53.0