From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 943BE3B8BC0; Thu, 15 Jan 2026 17:11:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768497063; cv=none; b=I8aVHDfexNkVYlcEMiB/bPb3ps0rv9xr9cfyE5/kYh3wp9DN0DU7fLDpGNplweALt/yivVAkXBo8JgWTZCYVbEF7185krfDDQRyPXh4xrBX9vvhi1ogGzvB6MTlZ4qT7XPtWaVPad4BBpS+R7q8Spre638SLRGxAP7LvHaQ27VA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768497063; c=relaxed/simple; bh=1r2xK6X82T5sWyjeg/eOqe5lNDGfh5enjv1DXCgQRlU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SBxxgzbZVKI9HslIU4FlBCXoq7YIi7YVGIx2uuSEjK+1tB/vY0CnCZRLjNRUFs0goIVg0Ucb2D9clb8bAUaLQFrzBaI+4fjbDU95LGzMjjuyglg3Pinp4OtF2CN8ru/yBpwlEter3aqapKF+mdLF17jYqnV0TvVhIN9KqaJdOe8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pf0WNzS6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="pf0WNzS6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 239FEC16AAE; Thu, 15 Jan 2026 17:11:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1768497063; bh=1r2xK6X82T5sWyjeg/eOqe5lNDGfh5enjv1DXCgQRlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pf0WNzS6ao6ac24lq2D/bidC0DZhOSWJShB4S80CjtYteKfyRHFd+15QQy/gecGXQ i6cUkJN4pV+J6eysWv7u6/I3apZuOEQvKDtpYe3mqV10f7yf3ibQQLf8+gA/ZQ40sc L/RndW4yevEe88UOVlQ7KDJcfkeafEeCuOuH//NY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ye Bin , Jan Kara , Theodore Tso , =?UTF-8?q?David=20Nystr=C3=B6m?= Subject: [PATCH 6.1 16/72] ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all() Date: Thu, 15 Jan 2026 17:48:26 +0100 Message-ID: <20260115164144.081804783@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260115164143.482647486@linuxfoundation.org> References: <20260115164143.482647486@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ye Bin [ Upstream commit 5701875f9609b000d91351eaa6bfd97fe2f157f4 ] There's issue as follows: BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790 Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172 CPU: 3 PID: 15172 Comm: syz-executor.0 Call Trace: __dump_stack lib/dump_stack.c:82 [inline] dump_stack+0xbe/0xfd lib/dump_stack.c:123 print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560 kasan_report+0x3a/0x50 mm/kasan/report.c:585 ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137 ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896 ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323 evict+0x39f/0x880 fs/inode.c:622 iput_final fs/inode.c:1746 [inline] iput fs/inode.c:1772 [inline] iput+0x525/0x6c0 fs/inode.c:1758 ext4_orphan_cleanup fs/ext4/super.c:3298 [inline] ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300 mount_bdev+0x355/0x410 fs/super.c:1446 legacy_get_tree+0xfe/0x220 fs/fs_context.c:611 vfs_get_tree+0x8d/0x2f0 fs/super.c:1576 do_new_mount fs/namespace.c:2983 [inline] path_mount+0x119a/0x1ad0 fs/namespace.c:3316 do_mount+0xfc/0x110 fs/namespace.c:3329 __do_sys_mount fs/namespace.c:3540 [inline] __se_sys_mount+0x219/0x2e0 fs/namespace.c:3514 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Memory state around the buggy address: ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Above issue happens as ext4_xattr_delete_inode() isn't check xattr is valid if xattr is in inode. To solve above issue call xattr_check_inode() check if xattr if valid in inode. In fact, we can directly verify in ext4_iget_extra_inode(), so that there is no divergent verification. Fixes: e50e5129f384 ("ext4: xattr-in-inode support") Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://patch.msgid.link/20250208063141.1539283-3-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: David Nyström Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 5 +++++ fs/ext4/xattr.c | 26 +------------------------- fs/ext4/xattr.h | 7 +++++++ 3 files changed, 13 insertions(+), 25 deletions(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4752,6 +4752,11 @@ static inline int ext4_iget_extra_inode( *magic == cpu_to_le32(EXT4_XATTR_MAGIC)) { int err; + err = xattr_check_inode(inode, IHDR(inode, raw_inode), + ITAIL(inode, raw_inode)); + if (err) + return err; + ext4_set_inode_state(inode, EXT4_STATE_XATTR); err = ext4_find_inline_data_nolock(inode); if (!err && ext4_has_inline_data(inode)) --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -263,7 +263,7 @@ errout: __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) -static int +int __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, void *end, const char *function, unsigned int line) { @@ -280,9 +280,6 @@ errout: return error; } -#define xattr_check_inode(inode, header, end) \ - __xattr_check_inode((inode), (header), (end), __func__, __LINE__) - static int xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, void *end, int name_index, const char *name, int sorted) @@ -600,9 +597,6 @@ ext4_xattr_ibody_get(struct inode *inode raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); end = ITAIL(inode, raw_inode); - error = xattr_check_inode(inode, header, end); - if (error) - goto cleanup; entry = IFIRST(header); error = xattr_find_entry(inode, &entry, end, name_index, name, 0); if (error) @@ -734,7 +728,6 @@ ext4_xattr_ibody_list(struct dentry *den struct ext4_xattr_ibody_header *header; struct ext4_inode *raw_inode; struct ext4_iloc iloc; - void *end; int error; if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) @@ -744,14 +737,9 @@ ext4_xattr_ibody_list(struct dentry *den return error; raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); - end = ITAIL(inode, raw_inode); - error = xattr_check_inode(inode, header, end); - if (error) - goto cleanup; error = ext4_xattr_list_entries(dentry, IFIRST(header), buffer, buffer_size); -cleanup: brelse(iloc.bh); return error; } @@ -819,7 +807,6 @@ int ext4_get_inode_usage(struct inode *i struct ext4_xattr_ibody_header *header; struct ext4_xattr_entry *entry; qsize_t ea_inode_refs = 0; - void *end; int ret; lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); @@ -830,10 +817,6 @@ int ext4_get_inode_usage(struct inode *i goto out; raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); - end = ITAIL(inode, raw_inode); - ret = xattr_check_inode(inode, header, end); - if (ret) - goto out; for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) @@ -2197,9 +2180,6 @@ int ext4_xattr_ibody_find(struct inode * is->s.here = is->s.first; is->s.end = ITAIL(inode, raw_inode); if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { - error = xattr_check_inode(inode, header, is->s.end); - if (error) - return error; /* Find the named attribute. */ error = xattr_find_entry(inode, &is->s.here, is->s.end, i->name_index, i->name, 0); @@ -2750,10 +2730,6 @@ retry: min_offs = end - base; total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32); - error = xattr_check_inode(inode, header, end); - if (error) - goto cleanup; - ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); if (ifree >= isize_diff) goto shift; --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -210,6 +210,13 @@ extern int ext4_xattr_ibody_set(handle_t extern struct mb_cache *ext4_xattr_create_cache(void); extern void ext4_xattr_destroy_cache(struct mb_cache *); +extern int +__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, + void *end, const char *function, unsigned int line); + +#define xattr_check_inode(inode, header, end) \ + __xattr_check_inode((inode), (header), (end), __func__, __LINE__) + #ifdef CONFIG_EXT4_FS_SECURITY extern int ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir, const struct qstr *qstr);