From: Zhong Jinghua zhongjinghua@huawei.com

hulk inclusion category: bugfix bugzilla: 187046, https://gitee.com/openeuler/kernel/issues/I5QH0X CVE: NA

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This reverts commit 1e9a49cfcc71112409dd40231ac614a809fffc38.

The mainline of this patch already exists, revert the interim patch

Signed-off-by: Zhong Jinghua zhongjinghua@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/quota/quota_tree.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c index 5389cabc6f20..3b5d2429b29c 100644 --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -79,12 +79,11 @@ static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf) return ret; }

-static inline int do_check_range(struct super_block *sb, uint val, - uint min_val, uint max_val) +static inline int do_check_range(struct super_block *sb, uint val, uint max_val) { - if (val < min_val || val >= max_val) { - quota_error(sb, "Getting block %u out of range %u-%u", - val, min_val, max_val); + if (val >= max_val) { + quota_error(sb, "Getting block too big (%u >= %u)", + val, max_val); return -EUCLEAN; }

@@ -98,11 +97,11 @@ static int check_free_block(struct qtree_mem_dqinfo *info, uint nextblk, prevblk;

nextblk = le32_to_cpu(dh->dqdh_next_free); - err = do_check_range(info->dqi_sb, nextblk, 0, info->dqi_blocks); + err = do_check_range(info->dqi_sb, nextblk, info->dqi_blocks); if (err) return err; prevblk = le32_to_cpu(dh->dqdh_prev_free); - err = do_check_range(info->dqi_sb, prevblk, 0, info->dqi_blocks); + err = do_check_range(info->dqi_sb, prevblk, info->dqi_blocks); if (err) return err;

@@ -527,10 +526,12 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot, goto out_buf; } newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); - ret = do_check_range(dquot->dq_sb, newblk, QT_TREEOFF, - info->dqi_blocks); - if (ret) + if (newblk < QT_TREEOFF || newblk >= info->dqi_blocks) { + quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)", + newblk, info->dqi_blocks); + ret = -EUCLEAN; goto out_buf; + }

if (depth == info->dqi_qtree_depth - 1) { ret = free_dqentry(info, dquot, newblk); @@ -631,9 +632,12 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info, blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); if (!blk) /* No reference? */ goto out_buf; - ret = do_check_range(dquot->dq_sb, blk, QT_TREEOFF, info->dqi_blocks); - if (ret) + if (blk < QT_TREEOFF || blk >= info->dqi_blocks) { + quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)", + blk, info->dqi_blocks); + ret = -EUCLEAN; goto out_buf; + }

if (depth < info->dqi_qtree_depth - 1) ret = find_tree_dqentry(info, dquot, blk, depth+1);

From: Zhihao Cheng chengzhihao1@huawei.com

mainline inclusion from mainline-v6.0-rc2 commit 6c8ea8b8cd4722efd419f91ca46a2dc81b7d89a3 category: bugfix bugzilla: 187046, https://gitee.com/openeuler/kernel/issues/I5QH0X CVE: NA

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Following process: Init: v2_read_file_info: <3> dqi_free_blk 0 dqi_free_entry 5 dqi_blks 6

Step 1. chown bin f_a -> dquot_acquire -> v2_write_dquot: qtree_write_dquot do_insert_tree find_free_dqentry get_free_dqblk write_blk(info->dqi_blocks) // info->dqi_blocks = 6, failure. The content in physical block (corresponding to blk 6) is random.

Step 2. chown root f_a -> dquot_transfer -> dqput_all -> dqput -> ext4_release_dquot -> v2_release_dquot -> qtree_delete_dquot: dquot_release remove_tree free_dqentry put_free_dqblk(6) info->dqi_free_blk = blk // info->dqi_free_blk = 6

Step 3. drop cache (buffer head for block 6 is released)

Step 4. chown bin f_b -> dquot_acquire -> commit_dqblk -> v2_write_dquot: qtree_write_dquot do_insert_tree find_free_dqentry get_free_dqblk dh = (struct qt_disk_dqdbheader *)buf blk = info->dqi_free_blk // 6 ret = read_blk(info, blk, buf) // The content of buf is random info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free) // random blk

Step 5. chown bin f_c -> notify_change -> ext4_setattr -> dquot_transfer: dquot = dqget -> acquire_dquot -> ext4_acquire_dquot -> dquot_acquire -> commit_dqblk -> v2_write_dquot -> dq_insert_tree: do_insert_tree find_free_dqentry get_free_dqblk blk = info->dqi_free_blk // If blk < 0 and blk is not an error code, it will be returned as dquot

transfer_to[USRQUOTA] = dquot // A random negative value __dquot_transfer(transfer_to) dquot_add_inodes(transfer_to[cnt]) spin_lock(&dquot->dq_dqb_lock) // page fault

, which will lead to kernel page fault: Quota error (device sda): qtree_write_dquot: Error -8000 occurred while creating quota BUG: unable to handle page fault for address: ffffffffffffe120 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 5974 Comm: chown Not tainted 6.0.0-rc1-00004 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:_raw_spin_lock+0x3a/0x90 Call Trace: dquot_add_inodes+0x28/0x270 __dquot_transfer+0x377/0x840 dquot_transfer+0xde/0x540 ext4_setattr+0x405/0x14d0 notify_change+0x68e/0x9f0 chown_common+0x300/0x430 __x64_sys_fchownat+0x29/0x40

In order to avoid accessing invalid quota memory address, this patch adds block number checking of next/prev free block read from quota file.

Fetch a reproducer in [Link].

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216372 Fixes: 1da177e4c3f4152 ("Linux-2.6.12-rc2") CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220923134555.2623931-2-chengzhihao1@huawei.com Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Zhong Jinghua zhongjinghua@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/quota/quota_tree.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)

diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c index 833cd3e3758b..ae2ed96d4847 100644 --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -79,6 +79,35 @@ static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf) return ret; }

+static inline int do_check_range(struct super_block *sb, const char *val_name, + uint val, uint min_val, uint max_val) +{ + if (val < min_val || val > max_val) { + quota_error(sb, "Getting %s %u out of range %u-%u", + val_name, val, min_val, max_val); + return -EUCLEAN; + } + + return 0; +} + +static int check_dquot_block_header(struct qtree_mem_dqinfo *info, + struct qt_disk_dqdbheader *dh) +{ + int err = 0; + + err = do_check_range(info->dqi_sb, "dqdh_next_free", + le32_to_cpu(dh->dqdh_next_free), 0, + info->dqi_blocks - 1); + if (err) + return err; + err = do_check_range(info->dqi_sb, "dqdh_prev_free", + le32_to_cpu(dh->dqdh_prev_free), 0, + info->dqi_blocks - 1); + + return err; +} + /* Remove empty block from list and return it */ static int get_free_dqblk(struct qtree_mem_dqinfo *info) { @@ -93,6 +122,9 @@ static int get_free_dqblk(struct qtree_mem_dqinfo *info) ret = read_blk(info, blk, buf); if (ret < 0) goto out_buf; + ret = check_dquot_block_header(info, dh); + if (ret) + goto out_buf; info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free); } else { @@ -240,6 +272,9 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info, *err = read_blk(info, blk, buf); if (*err < 0) goto out_buf; + *err = check_dquot_block_header(info, dh); + if (*err) + goto out_buf; } else { blk = get_free_dqblk(info); if ((int)blk < 0) { @@ -432,6 +467,9 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot, goto out_buf; } dh = (struct qt_disk_dqdbheader *)buf; + ret = check_dquot_block_header(info, dh); + if (ret) + goto out_buf; le16_add_cpu(&dh->dqdh_entries, -1); if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */ ret = remove_free_dqentry(info, buf, blk);

From: Zhihao Cheng chengzhihao1@huawei.com

mainline inclusion from mainline-v6.0-rc2 commit 191249f708897fc34c78f4494f7156896aaaeca9 category: bugfix bugzilla: 187046, https://gitee.com/openeuler/kernel/issues/I5QH0X CVE: NA

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It would be better to do more sanity checking (eg. dqdh_entries, block no.) for the content read from quota file, which can prevent corrupting the quota file.

Link: https://lore.kernel.org/r/20220923134555.2623931-4-chengzhihao1@huawei.com Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Zhong Jinghua zhongjinghua@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/quota/quota_tree.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c index 7dd007e84933..d376bde7ffb6 100644 --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -104,6 +104,11 @@ static int check_dquot_block_header(struct qtree_mem_dqinfo *info, err = do_check_range(info->dqi_sb, "dqdh_prev_free", le32_to_cpu(dh->dqdh_prev_free), 0, info->dqi_blocks - 1); + if (err) + return err; + err = do_check_range(info->dqi_sb, "dqdh_entries", + le16_to_cpu(dh->dqdh_entries), 0, + qtree_dqstr_in_blk(info));

return err; } @@ -356,6 +361,10 @@ static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot, } ref = (__le32 *)buf; newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); + ret = do_check_range(dquot->dq_sb, "block", newblk, 0, + info->dqi_blocks - 1); + if (ret) + goto out_buf; if (!newblk) newson = 1; if (depth == info->dqi_qtree_depth - 1) { @@ -747,15 +756,21 @@ static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id, goto out_buf; } for (i = __get_index(info, *id, depth); i < epb; i++) { - if (ref[i] == cpu_to_le32(0)) { + uint blk_no = le32_to_cpu(ref[i]); + + if (blk_no == 0) { *id += level_inc; continue; } + ret = do_check_range(info->dqi_sb, "block", blk_no, 0, + info->dqi_blocks - 1); + if (ret) + goto out_buf; if (depth == info->dqi_qtree_depth - 1) { ret = 0; goto out_buf; } - ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1); + ret = find_next_id(info, id, blk_no, depth + 1); if (ret != -ENOENT) break; }