threeeye
bc1d038eac
Squashed backup commit (no shallow-clone history issues) of xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream commit 9eece662e) plus all fixes applied to get everpal_defconfig building clean against a modern (GCC 15.2.0) toolchain -- see the previous commit message on the lineage-23.2 branch (also in this repo history is not available here since this is a squashed snapshot; full incremental history lives in the local DL380 checkout and the upstream GitHub remote). Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/security.h>
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#include <linux/sysctl.h>
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/* amount of vm to protect from userspace access by both DAC and the LSM*/
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unsigned long mmap_min_addr;
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/* amount of vm to protect from userspace using CAP_SYS_RAWIO (DAC) */
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unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
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/* amount of vm to protect from userspace using the LSM = CONFIG_LSM_MMAP_MIN_ADDR */
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/*
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* Update mmap_min_addr = max(dac_mmap_min_addr, CONFIG_LSM_MMAP_MIN_ADDR)
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*/
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static void update_mmap_min_addr(void)
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{
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#ifdef CONFIG_LSM_MMAP_MIN_ADDR
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if (dac_mmap_min_addr > CONFIG_LSM_MMAP_MIN_ADDR)
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mmap_min_addr = dac_mmap_min_addr;
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else
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mmap_min_addr = CONFIG_LSM_MMAP_MIN_ADDR;
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#else
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mmap_min_addr = dac_mmap_min_addr;
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#endif
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}
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/*
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* sysctl handler which just sets dac_mmap_min_addr = the new value and then
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* calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly
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*/
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int mmap_min_addr_handler(struct ctl_table *table, int write,
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void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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int ret;
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if (write && !capable(CAP_SYS_RAWIO))
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return -EPERM;
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ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
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update_mmap_min_addr();
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return ret;
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}
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static int __init init_mmap_min_addr(void)
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{
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update_mmap_min_addr();
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return 0;
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}
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pure_initcall(init_mmap_min_addr);
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