Commit f9c51bf4 authored by Baokun Li's avatar Baokun Li Committed by Yifan Qiao
Browse files

ext4: add new attr pointer attr_mb_order 

mainline inclusion
from mainline-v6.10-rc1
commit b7b2a5799b8fafe95fcd5455c32ba2c643c86f99
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAD018
CVE: CVE-2024-40955

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b7b2a5799b8fafe95fcd5455c32ba2c643c86f99



--------------------------------

The s_mb_best_avail_max_trim_order is of type unsigned int, and has a
range of values well beyond the normal use of the mb_order. Although the
mballoc code is careful enough that large numbers don't matter there, but
this can mislead the sysadmin into thinking that it's normal to set such
values. Hence add a new attr_id attr_mb_order with values in the range
[0, 64] to avoid storing garbage values and make us more resilient to
surprises in the future.

Suggested-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarBaokun Li <libaokun1@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240319113325.3110393-6-libaokun1@huawei.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarYifan Qiao <qiaoyifan4@huawei.com>
parent a5ea1f3c

fs/ext4/sysfs.c

+12 −1
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ typedef enum { 
	attr_first_error_time,

	attr_last_error_time,

	attr_clusters_in_group,

	attr_mb_order,

	attr_feature,

	attr_pointer_ui,

	attr_pointer_ul,
@@ -210,6 +211,8 @@ EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead, 
		 ext4_sb_info, s_inode_readahead_blks);

EXT4_ATTR_OFFSET(mb_group_prealloc, 0644, clusters_in_group,

		 ext4_sb_info, s_mb_group_prealloc);

EXT4_ATTR_OFFSET(mb_best_avail_max_trim_order, 0644, mb_order,

		 ext4_sb_info, s_mb_best_avail_max_trim_order);

EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);

EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);

EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
@@ -225,7 +228,6 @@ EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.int 
EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);

EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);

EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);

EXT4_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order);

#ifdef CONFIG_EXT4_DEBUG

EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);

#endif
@@ -379,6 +381,7 @@ static ssize_t ext4_generic_attr_show(struct ext4_attr *a, 
	switch (a->attr_id) {

	case attr_inode_readahead:

	case attr_clusters_in_group:

	case attr_mb_order:

	case attr_pointer_ui:

		if (a->attr_ptr == ptr_ext4_super_block_offset)

			return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr));
@@ -458,6 +461,14 @@ static ssize_t ext4_generic_attr_store(struct ext4_attr *a, 
		else

			*((unsigned int *) ptr) = t;

		return len;

	case attr_mb_order:

		ret = kstrtouint(skip_spaces(buf), 0, &t);

		if (ret)

			return ret;

		if (t > 64)

			return -EINVAL;

		*((unsigned int *) ptr) = t;

		return len;

	case attr_clusters_in_group:

		ret = kstrtouint(skip_spaces(buf), 0, &t);

		if (ret)