From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 005AC155316 for ; Sat, 8 Feb 2025 06:31:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738996315; cv=none; b=FSkXqrZOhuiPaVAMtSEP8Ng5Uq5wPAyuXiqMZluxQXkocz48RZlE0Jej2H7WCAM80BogY5NllinXPWPKjW+ilUGrql+fH/ZxpOnOd9/QkCOFJhPkXwOtaf8wks72NtUNIZGLLAHT6YnAFZ24fEo9u9RPhM5V+++7fzIzPTdGCHU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738996315; c=relaxed/simple; bh=NyQjkdjXQ04xdBDTPqNOxsv+TLsrRX3E/ReeuecVxA8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=L6BIJddTxTTF8lbxApTHDhUAk1Ag/BfDUaAIMEqqZ4khCyCk/z+Maj7HsDCpf97vDeCSDaWCoOHQlIgQ892fo/N70+s42WOC8IYafOaAGMhxj72WnC9E93wERdrs7q+jwI14N3FI4Cy0vth6Z2JJ9WN2cJtEC8ih5tE+LT0IeBg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4YqgwB6l0vz4f3jdF for ; Sat, 8 Feb 2025 14:31:22 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 29DD41A111F for ; Sat, 8 Feb 2025 14:31:44 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.101.107]) by APP4 (Coremail) with SMTP id gCh0CgBXvGBN+qZnQ2X1DA--.63634S6; Sat, 08 Feb 2025 14:31:44 +0800 (CST) From: Ye Bin To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Cc: jack@suse.cz Subject: [PATCH v2 2/2] ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all() Date: Sat, 8 Feb 2025 14:31:41 +0800 Message-Id: <20250208063141.1539283-3-yebin@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250208063141.1539283-1-yebin@huaweicloud.com> References: <20250208063141.1539283-1-yebin@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:gCh0CgBXvGBN+qZnQ2X1DA--.63634S6 X-Coremail-Antispam: 1UD129KBjvJXoW3Xr48Jry5uF4rJw17XFyfCrg_yoW3Jryfp3 W3t34UCr48XryUWrWIyr13Zw1ag3W7CayUZayxGry8AFy5Wwn7tFyFkF15CF1DArW8G3W2 qFs8Jr4j93WfC3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvlb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvE x4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvj DU0xZFpf9x07URpBfUUUUU= X-CM-SenderInfo: p1hex046kxt4xhlfz01xgou0bp/ From: Ye Bin 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 --- fs/ext4/inode.c | 5 +++++ fs/ext4/xattr.c | 26 +------------------------- fs/ext4/xattr.h | 7 +++++++ 3 files changed, 13 insertions(+), 25 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 7c54ae5fcbd4..af735386aa44 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4674,6 +4674,11 @@ static inline int ext4_iget_extra_inode(struct inode *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)) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 0e4494863d15..a10fb8a9d02d 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -308,7 +308,7 @@ __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) -static inline int +int __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, void *end, const char *function, unsigned int line) { @@ -316,9 +316,6 @@ __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, function, line); } -#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) @@ -650,9 +647,6 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 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) @@ -783,7 +777,6 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 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)) @@ -793,14 +786,9 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 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; } @@ -868,7 +856,6 @@ int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 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); @@ -879,10 +866,6 @@ int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 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)) @@ -2237,9 +2220,6 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 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); @@ -2790,10 +2770,6 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 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; diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 5197f17ffd9a..1fedf44d4fb6 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -209,6 +209,13 @@ extern int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 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); -- 2.34.1