Commit da4e7421 authored by Baokun Li's avatar Baokun Li Committed by Yifan Qiao
Browse files

ext4: add positive int attr pointer to avoid sysfs variables overflow 

mainline inclusion
from mainline-v6.10-rc1
commit 63bfe841053f8dda09c9d059d543486d9dc16104
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=63bfe841053f8dda09c9d059d543486d9dc16104



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

The following variables controlled by the sysfs interface are of type
int and are normally used in the range [0, INT_MAX], but are declared as
attr_pointer_ui, and thus may be set to values that exceed INT_MAX and
result in overflows to get negative values.

  err_ratelimit_burst
  msg_ratelimit_burst
  warning_ratelimit_burst
  err_ratelimit_interval_ms
  msg_ratelimit_interval_ms
  warning_ratelimit_interval_ms

Therefore, we add attr_pointer_pi (aka positive int attr pointer) with a
value range of 0-INT_MAX to avoid overflow.

Signed-off-by: default avatarBaokun Li <libaokun1@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240319113325.3110393-7-libaokun1@huawei.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarYifan Qiao <qiaoyifan4@huawei.com>
parent f9c51bf4

fs/ext4/sysfs.c

+19 −6
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ typedef enum { 
	attr_clusters_in_group,

	attr_mb_order,

	attr_feature,

	attr_pointer_pi,

	attr_pointer_ui,

	attr_pointer_ul,

	attr_pointer_u64,
@@ -180,6 +181,9 @@ static struct ext4_attr ext4_attr_##_name = { \ 
#define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size)			\

	EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname)



#define EXT4_RW_ATTR_SBI_PI(_name,_elname)      \

	EXT4_ATTR_OFFSET(_name, 0644, pointer_pi, ext4_sb_info, _elname)



#define EXT4_RW_ATTR_SBI_UI(_name,_elname)	\

	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
@@ -222,12 +226,12 @@ EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); 
EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);

EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);

EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);

EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);

EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);

EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);

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_PI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);

EXT4_RW_ATTR_SBI_PI(err_ratelimit_burst, s_err_ratelimit_state.burst);

EXT4_RW_ATTR_SBI_PI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);

EXT4_RW_ATTR_SBI_PI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);

EXT4_RW_ATTR_SBI_PI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);

EXT4_RW_ATTR_SBI_PI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);

#ifdef CONFIG_EXT4_DEBUG

EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);

#endif
@@ -382,6 +386,7 @@ static ssize_t ext4_generic_attr_show(struct ext4_attr *a, 
	case attr_inode_readahead:

	case attr_clusters_in_group:

	case attr_mb_order:

	case attr_pointer_pi:

	case attr_pointer_ui:

		if (a->attr_ptr == ptr_ext4_super_block_offset)

			return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr));
@@ -452,6 +457,14 @@ static ssize_t ext4_generic_attr_store(struct ext4_attr *a, 
		return 0;



	switch (a->attr_id) {

	case attr_pointer_pi:

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

		if (ret)

			return ret;

		if ((int)t < 0)

			return -EINVAL;

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

		return len;

	case attr_pointer_ui:

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

		if (ret)