From 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 2 Sep 2026 15:31:14 -0700 Subject: treewide: refresh kmalloc_obj() conversions This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook --- security/min_addr.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 security/min_addr.c (limited to 'security/min_addr.c') diff --git a/security/min_addr.c b/security/min_addr.c new file mode 100644 index 000000000..56e4f9d25 --- /dev/null +++ b/security/min_addr.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +/* amount of vm to protect from userspace access by both DAC and the LSM*/ +unsigned long mmap_min_addr; +/* amount of vm to protect from userspace using CAP_SYS_RAWIO (DAC) */ +unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; +/* amount of vm to protect from userspace using the LSM = CONFIG_LSM_MMAP_MIN_ADDR */ + +/* + * Update mmap_min_addr = max(dac_mmap_min_addr, CONFIG_LSM_MMAP_MIN_ADDR) + */ +static void update_mmap_min_addr(void) +{ +#ifdef CONFIG_LSM_MMAP_MIN_ADDR + mmap_min_addr = umax(dac_mmap_min_addr, CONFIG_LSM_MMAP_MIN_ADDR); +#else + mmap_min_addr = dac_mmap_min_addr; +#endif +} + +/* + * sysctl handler which just sets dac_mmap_min_addr = the new value and then + * calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly + */ +int mmap_min_addr_handler(const struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int ret; + + if (write && !capable(CAP_SYS_RAWIO)) + return -EPERM; + + ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos); + + update_mmap_min_addr(); + + return ret; +} + +static const struct ctl_table min_addr_sysctl_table[] = { + { + .procname = "mmap_min_addr", + .data = &dac_mmap_min_addr, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = mmap_min_addr_handler, + }, +}; + +static int __init mmap_min_addr_init(void) +{ + register_sysctl_init("vm", min_addr_sysctl_table); + update_mmap_min_addr(); + + return 0; +} +pure_initcall(mmap_min_addr_init); -- cgit v1.3.1