kernel: increase reliability, add ksu_access_ok to simplify

Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Signed-off-by: rsuntk <rsuntk@yukiprjkt.my.id>
This commit is contained in:
ShirkNeko
2025-08-03 23:19:35 +08:00
parent 98552980ca
commit f37092e2f0
4 changed files with 18 additions and 19 deletions

View File

@@ -79,15 +79,6 @@ void ksu_android_ns_fs_check()
task_unlock(current);
}
int ksu_access_ok(const void *addr, unsigned long size) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(5,0,0)
/* For kernels before 5.0.0, pass the type argument to access_ok. */
return access_ok(VERIFY_READ, addr, size);
#else
/* For kernels 5.0.0 and later, ignore the type argument. */
return access_ok(addr, size);
#endif
}
struct file *ksu_filp_open_compat(const char *filename, int flags, umode_t mode)
{
@@ -188,3 +179,12 @@ long ksu_strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
return ret;
}
#endif
int ksu_access_ok(const void *addr, unsigned long size)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
return access_ok(addr, size);
#else
return access_ok(VERIFY_READ, addr, size);
#endif
}

View File

@@ -58,12 +58,11 @@ extern struct key *init_session_keyring;
#endif
extern void ksu_android_ns_fs_check();
extern int ksu_access_ok(const void *addr, unsigned long size);
extern struct file *ksu_filp_open_compat(const char *filename, int flags,
umode_t mode);
extern ssize_t ksu_kernel_read_compat(struct file *p, void *buf, size_t count,
loff_t *pos);
extern ssize_t ksu_kernel_write_compat(struct file *p, const void *buf,
size_t count, loff_t *pos);
extern int ksu_access_ok(const void *addr, unsigned long size);
#endif

View File

@@ -586,6 +586,7 @@ static int ksu_execve_ksud_common(const char __user *filename_user,
{
struct filename filename_in, *filename_p;
char path[32];
long len;
// return early if disabled.
if (!ksu_execveat_hook) {
@@ -595,8 +596,11 @@ static int ksu_execve_ksud_common(const char __user *filename_user,
if (!filename_user)
return 0;
memset(path, 0, sizeof(path));
ksu_strncpy_from_user_nofault(path, filename_user, 32);
len = ksu_strncpy_from_user_nofault(path, filename_user, 32);
if (len <= 0)
return 0;
path[sizeof(path) - 1] = '\0';
// this is because ksu_handle_execveat_ksud calls it filename->name
filename_in.name = path;

View File

@@ -218,13 +218,9 @@ int ksu_handle_execve_sucompat(int *fd, const char __user **filename_user,
* some cpus dont really have that good speculative execution
* access_ok to substitute set_fs, we check if pointer is accessible
*/
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
if (!access_ok(VERIFY_READ, *filename_user, sizeof(path)))
if (!ksu_access_ok((const void *)filename_user, sizeof(path)))
return 0;
#else
if (!access_ok(*filename_user, sizeof(path)))
return 0;
#endif
// success = returns number of bytes and should be less than path
long len = strncpy_from_user(path, *filename_user, sizeof(path));
if (len <= 0 || len > sizeof(path))