kernel/stackleak.c:33:50: sparse: sparse: incorrect type in argument 3 (different address spaces)

From: kernel test robot
Date: Tue Mar 21 2023 - 16:19:42 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 2faac9a98f010cf5b342fa89ac489c4586364e6e
commit: 0df8bdd5e3b3e557ce2c2575fce0c64c5dd1045a stackleak: move stack_erasing sysctl to stackleak.c
date: 1 year, 2 months ago
config: arm64-randconfig-s032-20230321 (https://download.01.org/0day-ci/archive/20230322/202303220449.l6Q32ILq-lkp@xxxxxxxxx/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0df8bdd5e3b3e557ce2c2575fce0c64c5dd1045a
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 0df8bdd5e3b3e557ce2c2575fce0c64c5dd1045a
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202303220449.l6Q32ILq-lkp@xxxxxxxxx/

sparse warnings: (new ones prefixed by >>)
>> kernel/stackleak.c:33:50: sparse: sparse: incorrect type in argument 3 (different address spaces) @@ expected void * @@ got void [noderef] __user *buffer @@
kernel/stackleak.c:33:50: sparse: expected void *
kernel/stackleak.c:33:50: sparse: got void [noderef] __user *buffer
>> kernel/stackleak.c:53:35: sparse: sparse: incorrect type in initializer (incompatible argument 3 (different address spaces)) @@ expected int ( [usertype] *proc_handler )( ... ) @@ got int ( * )( ... ) @@
kernel/stackleak.c:53:35: sparse: expected int ( [usertype] *proc_handler )( ... )
kernel/stackleak.c:53:35: sparse: got int ( * )( ... )

vim +33 kernel/stackleak.c

964c9dff0091893 Alexander Popov 2018-08-17 22
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 23 #ifdef CONFIG_SYSCTL
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 24 static int stack_erasing_sysctl(struct ctl_table *table, int write,
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 25 void __user *buffer, size_t *lenp, loff_t *ppos)
964c9dff0091893 Alexander Popov 2018-08-17 26 {
964c9dff0091893 Alexander Popov 2018-08-17 27 int ret = 0;
964c9dff0091893 Alexander Popov 2018-08-17 28 int state = !static_branch_unlikely(&stack_erasing_bypass);
964c9dff0091893 Alexander Popov 2018-08-17 29 int prev_state = state;
964c9dff0091893 Alexander Popov 2018-08-17 30
964c9dff0091893 Alexander Popov 2018-08-17 31 table->data = &state;
964c9dff0091893 Alexander Popov 2018-08-17 32 table->maxlen = sizeof(int);
964c9dff0091893 Alexander Popov 2018-08-17 @33 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
964c9dff0091893 Alexander Popov 2018-08-17 34 state = !!state;
964c9dff0091893 Alexander Popov 2018-08-17 35 if (ret || !write || state == prev_state)
964c9dff0091893 Alexander Popov 2018-08-17 36 return ret;
964c9dff0091893 Alexander Popov 2018-08-17 37
964c9dff0091893 Alexander Popov 2018-08-17 38 if (state)
964c9dff0091893 Alexander Popov 2018-08-17 39 static_branch_disable(&stack_erasing_bypass);
964c9dff0091893 Alexander Popov 2018-08-17 40 else
964c9dff0091893 Alexander Popov 2018-08-17 41 static_branch_enable(&stack_erasing_bypass);
964c9dff0091893 Alexander Popov 2018-08-17 42
964c9dff0091893 Alexander Popov 2018-08-17 43 pr_warn("stackleak: kernel stack erasing is %s\n",
964c9dff0091893 Alexander Popov 2018-08-17 44 state ? "enabled" : "disabled");
964c9dff0091893 Alexander Popov 2018-08-17 45 return ret;
964c9dff0091893 Alexander Popov 2018-08-17 46 }
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 47 static struct ctl_table stackleak_sysctls[] = {
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 48 {
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 49 .procname = "stack_erasing",
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 50 .data = NULL,
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 51 .maxlen = sizeof(int),
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 52 .mode = 0600,
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 @53 .proc_handler = stack_erasing_sysctl,
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 54 .extra1 = SYSCTL_ZERO,
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 55 .extra2 = SYSCTL_ONE,
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 56 },
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 57 {}
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 58 };
0df8bdd5e3b3e55 Xiaoming Ni 2022-01-21 59

:::::: The code at line 33 was first introduced by commit
:::::: 964c9dff0091893a9a74a88edf984c6da0b779f7 stackleak: Allow runtime disabling of kernel stack erasing

:::::: TO: Alexander Popov <alex.popov@xxxxxxxxx>
:::::: CC: Kees Cook <keescook@xxxxxxxxxxxx>

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests