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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-10 16:02:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-10 16:02:54 -0700
commit4382a79b2746faf9db98a34ae1a1cbd364473f75 (patch)
tree1bd6e40c0120cef455b6e6294df0cea10fe13be0
parent79ca035d2d941839f55f3b8b69f8e81c66946ed8 (diff)
parentb7e4b65f3fe92abbf4a1f57987a54c820969aebd (diff)
Merge branch 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc uaccess updates from Al Viro: "Assorted uaccess patches for this cycle - the stuff that didn't fit into thematic series" * 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user() x86: kvm_hv_set_msr(): use __put_user() instead of 32bit __clear_user() user_regset_copyout_zero(): use clear_user() TEST_ACCESS_OK _never_ had been checked anywhere x86: switch cp_stat64() to unsafe_put_user() binfmt_flat: don't use __put_user() binfmt_elf_fdpic: don't use __... uaccess primitives binfmt_elf: don't bother with __{put,copy_to}_user() pselect6() and friends: take handling the combined 6th/7th args into helper
-rw-r--r--arch/x86/include/asm/pgtable_32.h7
-rw-r--r--arch/x86/kernel/sys_ia32.c40
-rw-r--r--arch/x86/kvm/hyperv.c2
-rw-r--r--fs/binfmt_elf.c16
-rw-r--r--fs/binfmt_elf_fdpic.c31
-rw-r--r--fs/binfmt_flat.c22
-rw-r--r--fs/select.c112
-rw-r--r--include/linux/regset.h2
-rw-r--r--kernel/bpf/syscall.c25
9 files changed, 135 insertions, 122 deletions
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index ef76a04b4daf..d7acae4120d5 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -32,13 +32,6 @@ extern pmd_t initial_pg_pmd[];
void paging_init(void);
void sync_initial_page_table(void);
-/*
- * Define this if things work differently on an i386 and an i486:
- * it will (on an i486) warn about kernel memory accesses that are
- * done without a 'access_ok( ..)'
- */
-#undef TEST_ACCESS_OK
-
#ifdef CONFIG_X86_PAE
# include <asm/pgtable-3level.h>
#else
diff --git a/arch/x86/kernel/sys_ia32.c b/arch/x86/kernel/sys_ia32.c
index ab03fede1422..f8d65c99feb8 100644
--- a/arch/x86/kernel/sys_ia32.c
+++ b/arch/x86/kernel/sys_ia32.c
@@ -135,26 +135,30 @@ static int cp_stat64(struct stat64 __user *ubuf, struct kstat *stat)
typeof(ubuf->st_gid) gid = 0;
SET_UID(uid, from_kuid_munged(current_user_ns(), stat->uid));
SET_GID(gid, from_kgid_munged(current_user_ns(), stat->gid));
- if (!access_ok(ubuf, sizeof(struct stat64)) ||
- __put_user(huge_encode_dev(stat->dev), &ubuf->st_dev) ||
- __put_user(stat->ino, &ubuf->__st_ino) ||
- __put_user(stat->ino, &ubuf->st_ino) ||
- __put_user(stat->mode, &ubuf->st_mode) ||
- __put_user(stat->nlink, &ubuf->st_nlink) ||
- __put_user(uid, &ubuf->st_uid) ||
- __put_user(gid, &ubuf->st_gid) ||
- __put_user(huge_encode_dev(stat->rdev), &ubuf->st_rdev) ||
- __put_user(stat->size, &ubuf->st_size) ||
- __put_user(stat->atime.tv_sec, &ubuf->st_atime) ||
- __put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec) ||
- __put_user(stat->mtime.tv_sec, &ubuf->st_mtime) ||
- __put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec) ||
- __put_user(stat->ctime.tv_sec, &ubuf->st_ctime) ||
- __put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec) ||
- __put_user(stat->blksize, &ubuf->st_blksize) ||
- __put_user(stat->blocks, &ubuf->st_blocks))
+ if (!user_write_access_begin(ubuf, sizeof(struct stat64)))
return -EFAULT;
+ unsafe_put_user(huge_encode_dev(stat->dev), &ubuf->st_dev, Efault);
+ unsafe_put_user(stat->ino, &ubuf->__st_ino, Efault);
+ unsafe_put_user(stat->ino, &ubuf->st_ino, Efault);
+ unsafe_put_user(stat->mode, &ubuf->st_mode, Efault);
+ unsafe_put_user(stat->nlink, &ubuf->st_nlink, Efault);
+ unsafe_put_user(uid, &ubuf->st_uid, Efault);
+ unsafe_put_user(gid, &ubuf->st_gid, Efault);
+ unsafe_put_user(huge_encode_dev(stat->rdev), &ubuf->st_rdev, Efault);
+ unsafe_put_user(stat->size, &ubuf->st_size, Efault);
+ unsafe_put_user(stat->atime.tv_sec, &ubuf->st_atime, Efault);
+ unsafe_put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec, Efault);
+ unsafe_put_user(stat->mtime.tv_sec, &ubuf->st_mtime, Efault);
+ unsafe_put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec, Efault);
+ unsafe_put_user(stat->ctime.tv_sec, &ubuf->st_ctime, Efault);
+ unsafe_put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec, Efault);
+ unsafe_put_user(stat->blksize, &ubuf->st_blksize, Efault);
+ unsafe_put_user(stat->blocks, &ubuf->st_blocks, Efault);
+ user_access_end();
return 0;
+Efault:
+ user_write_access_end();
+ return -EFAULT;
}
COMPAT_SYSCALL_DEFINE2(ia32_stat64, const char __user *, filename,
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 238b78e069fe..af9cdb426dd2 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1252,7 +1252,7 @@ static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
* only, there can be valuable data in the rest which needs
* to be preserved e.g. on migration.
*/
- if (__clear_user((void __user *)addr, sizeof(u32)))
+ if (__put_user(0, (u32 __user *)addr))
return 1;
hv_vcpu->hv_vapic = data;
kvm_vcpu_mark_page_dirty(vcpu, gfn);
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index e5d50bd880e9..9fe3b51c116a 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -208,7 +208,7 @@ create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
size_t len = strlen(k_platform) + 1;
u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
- if (__copy_to_user(u_platform, k_platform, len))
+ if (copy_to_user(u_platform, k_platform, len))
return -EFAULT;
}
@@ -221,7 +221,7 @@ create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
size_t len = strlen(k_base_platform) + 1;
u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
- if (__copy_to_user(u_base_platform, k_base_platform, len))
+ if (copy_to_user(u_base_platform, k_base_platform, len))
return -EFAULT;
}
@@ -231,7 +231,7 @@ create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
u_rand_bytes = (elf_addr_t __user *)
STACK_ALLOC(p, sizeof(k_rand_bytes));
- if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
+ if (copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
return -EFAULT;
/* Create the ELF interpreter info */
@@ -314,21 +314,21 @@ create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
return -EFAULT;
/* Now, let's put argc (and argv, envp if appropriate) on the stack */
- if (__put_user(argc, sp++))
+ if (put_user(argc, sp++))
return -EFAULT;
/* Populate list of argv pointers back to argv strings. */
p = mm->arg_end = mm->arg_start;
while (argc-- > 0) {
size_t len;
- if (__put_user((elf_addr_t)p, sp++))
+ if (put_user((elf_addr_t)p, sp++))
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- if (__put_user(0, sp++))
+ if (put_user(0, sp++))
return -EFAULT;
mm->arg_end = p;
@@ -336,14 +336,14 @@ create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
mm->env_end = mm->env_start = p;
while (envc-- > 0) {
size_t len;
- if (__put_user((elf_addr_t)p, sp++))
+ if (put_user((elf_addr_t)p, sp++))
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- if (__put_user(0, sp++))
+ if (put_user(0, sp++))
return -EFAULT;
mm->env_end = p;
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index aaf332d32326..0f45521b237c 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -536,7 +536,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
platform_len = strlen(k_platform) + 1;
sp -= platform_len;
u_platform = (char __user *) sp;
- if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
+ if (copy_to_user(u_platform, k_platform, platform_len) != 0)
return -EFAULT;
}
@@ -551,7 +551,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
platform_len = strlen(k_base_platform) + 1;
sp -= platform_len;
u_base_platform = (char __user *) sp;
- if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
+ if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
return -EFAULT;
}
@@ -603,11 +603,13 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
/* put the ELF interpreter info on the stack */
#define NEW_AUX_ENT(id, val) \
do { \
- struct { unsigned long _id, _val; } __user *ent; \
+ struct { unsigned long _id, _val; } __user *ent, v; \
\
ent = (void __user *) csp; \
- __put_user((id), &ent[nr]._id); \
- __put_user((val), &ent[nr]._val); \
+ v._id = (id); \
+ v._val = (val); \
+ if (copy_to_user(ent + nr, &v, sizeof(v))) \
+ return -EFAULT; \
nr++; \
} while (0)
@@ -674,7 +676,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
/* stack argc */
csp -= sizeof(unsigned long);
- __put_user(bprm->argc, (unsigned long __user *) csp);
+ if (put_user(bprm->argc, (unsigned long __user *) csp))
+ return -EFAULT;
BUG_ON(csp != sp);
@@ -688,25 +691,29 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
p = (char __user *) current->mm->arg_start;
for (loop = bprm->argc; loop > 0; loop--) {
- __put_user((elf_caddr_t) p, argv++);
+ if (put_user((elf_caddr_t) p, argv++))
+ return -EFAULT;
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- __put_user(NULL, argv);
+ if (put_user(NULL, argv))
+ return -EFAULT;
current->mm->arg_end = (unsigned long) p;
/* fill in the envv[] array */
current->mm->env_start = (unsigned long) p;
for (loop = bprm->envc; loop > 0; loop--) {
- __put_user((elf_caddr_t)(unsigned long) p, envp++);
+ if (put_user((elf_caddr_t)(unsigned long) p, envp++))
+ return -EFAULT;
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- __put_user(NULL, envp);
+ if (put_user(NULL, envp))
+ return -EFAULT;
current->mm->env_end = (unsigned long) p;
mm->start_stack = (unsigned long) sp;
@@ -848,8 +855,8 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
dyn = (Elf32_Dyn __user *)params->dynamic_addr;
- __get_user(d_tag, &dyn[tmp - 1].d_tag);
- if (d_tag != 0)
+ if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
+ d_tag != 0)
goto dynamic_error;
break;
}
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 87ce229c63cf..f2f9086ebe98 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -138,35 +138,40 @@ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start
current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
sp = (unsigned long __user *)current->mm->start_stack;
- __put_user(bprm->argc, sp++);
+ if (put_user(bprm->argc, sp++))
+ return -EFAULT;
if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
unsigned long argv, envp;
argv = (unsigned long)(sp + 2);
envp = (unsigned long)(sp + 2 + bprm->argc + 1);
- __put_user(argv, sp++);
- __put_user(envp, sp++);
+ if (put_user(argv, sp++) || put_user(envp, sp++))
+ return -EFAULT;
}
current->mm->arg_start = (unsigned long)p;
for (i = bprm->argc; i > 0; i--) {
- __put_user((unsigned long)p, sp++);
+ if (put_user((unsigned long)p, sp++))
+ return -EFAULT;
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- __put_user(0, sp++);
+ if (put_user(0, sp++))
+ return -EFAULT;
current->mm->arg_end = (unsigned long)p;
current->mm->env_start = (unsigned long) p;
for (i = bprm->envc; i > 0; i--) {
- __put_user((unsigned long)p, sp++);
+ if (put_user((unsigned long)p, sp++))
+ return -EFAULT;
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- __put_user(0, sp++);
+ if (put_user(0, sp++))
+ return -EFAULT;
current->mm->env_end = (unsigned long)p;
return 0;
@@ -996,7 +1001,8 @@ static int load_flat_binary(struct linux_binprm *bprm)
unsigned long __user *sp;
current->mm->start_stack -= sizeof(unsigned long);
sp = (unsigned long __user *)current->mm->start_stack;
- __put_user(start_addr, sp);
+ if (put_user(start_addr, sp))
+ return -EFAULT;
start_addr = libinfo.lib_list[i].entry;
}
}
diff --git a/fs/select.c b/fs/select.c
index 11d0285d46b7..7aef49552d4c 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -766,22 +766,38 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
* which has a pointer to the sigset_t itself followed by a size_t containing
* the sigset size.
*/
+struct sigset_argpack {
+ sigset_t __user *p;
+ size_t size;
+};
+
+static inline int get_sigset_argpack(struct sigset_argpack *to,
+ struct sigset_argpack __user *from)
+{
+ // the path is hot enough for overhead of copy_from_user() to matter
+ if (from) {
+ if (!user_read_access_begin(from, sizeof(*from)))
+ return -EFAULT;
+ unsafe_get_user(to->p, &from->p, Efault);
+ unsafe_get_user(to->size, &from->size, Efault);
+ user_read_access_end();
+ }
+ return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
+
SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp,
fd_set __user *, exp, struct __kernel_timespec __user *, tsp,
void __user *, sig)
{
- size_t sigsetsize = 0;
- sigset_t __user *up = NULL;
-
- if (sig) {
- if (!access_ok(sig, sizeof(void *)+sizeof(size_t))
- || __get_user(up, (sigset_t __user * __user *)sig)
- || __get_user(sigsetsize,
- (size_t __user *)(sig+sizeof(void *))))
- return -EFAULT;
- }
+ struct sigset_argpack x = {NULL, 0};
+
+ if (get_sigset_argpack(&x, sig))
+ return -EFAULT;
- return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize, PT_TIMESPEC);
+ return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC);
}
#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
@@ -790,18 +806,12 @@ SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *,
fd_set __user *, exp, struct old_timespec32 __user *, tsp,
void __user *, sig)
{
- size_t sigsetsize = 0;
- sigset_t __user *up = NULL;
-
- if (sig) {
- if (!access_ok(sig, sizeof(void *)+sizeof(size_t))
- || __get_user(up, (sigset_t __user * __user *)sig)
- || __get_user(sigsetsize,
- (size_t __user *)(sig+sizeof(void *))))
- return -EFAULT;
- }
+ struct sigset_argpack x = {NULL, 0};
+
+ if (get_sigset_argpack(&x, sig))
+ return -EFAULT;
- return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize, PT_OLD_TIMESPEC);
+ return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC);
}
#endif
@@ -1325,24 +1335,37 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp,
return poll_select_finish(&end_time, tsp, type, ret);
}
+struct compat_sigset_argpack {
+ compat_uptr_t p;
+ compat_size_t size;
+};
+static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,
+ struct compat_sigset_argpack __user *from)
+{
+ if (from) {
+ if (!user_read_access_begin(from, sizeof(*from)))
+ return -EFAULT;
+ unsafe_get_user(to->p, &from->p, Efault);
+ unsafe_get_user(to->size, &from->size, Efault);
+ user_read_access_end();
+ }
+ return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
+
COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp,
compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
struct __kernel_timespec __user *, tsp, void __user *, sig)
{
- compat_size_t sigsetsize = 0;
- compat_uptr_t up = 0;
-
- if (sig) {
- if (!access_ok(sig,
- sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||
- __get_user(up, (compat_uptr_t __user *)sig) ||
- __get_user(sigsetsize,
- (compat_size_t __user *)(sig+sizeof(up))))
- return -EFAULT;
- }
+ struct compat_sigset_argpack x = {0, 0};
+
+ if (get_compat_sigset_argpack(&x, sig))
+ return -EFAULT;
- return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up),
- sigsetsize, PT_TIMESPEC);
+ return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),
+ x.size, PT_TIMESPEC);
}
#if defined(CONFIG_COMPAT_32BIT_TIME)
@@ -1351,20 +1374,13 @@ COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp,
compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
struct old_timespec32 __user *, tsp, void __user *, sig)
{
- compat_size_t sigsetsize = 0;
- compat_uptr_t up = 0;
-
- if (sig) {
- if (!access_ok(sig,
- sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||
- __get_user(up, (compat_uptr_t __user *)sig) ||
- __get_user(sigsetsize,
- (compat_size_t __user *)(sig+sizeof(up))))
- return -EFAULT;
- }
+ struct compat_sigset_argpack x = {0, 0};
+
+ if (get_compat_sigset_argpack(&x, sig))
+ return -EFAULT;
- return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up),
- sigsetsize, PT_OLD_TIMESPEC);
+ return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),
+ x.size, PT_OLD_TIMESPEC);
}
#endif
diff --git a/include/linux/regset.h b/include/linux/regset.h
index bf0243779738..46d6ae68c455 100644
--- a/include/linux/regset.h
+++ b/include/linux/regset.h
@@ -320,7 +320,7 @@ static inline int user_regset_copyout_zero(unsigned int *pos,
if (*kbuf) {
memset(*kbuf, 0, copy);
*kbuf += copy;
- } else if (__clear_user(*ubuf, copy))
+ } else if (clear_user(*ubuf, copy))
return -EFAULT;
else
*ubuf += copy;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c3ae2adaeccd..9693730833d2 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -74,32 +74,19 @@ int bpf_check_uarg_tail_zero(void __user *uaddr,
size_t expected_size,
size_t actual_size)
{
- unsigned char __user *addr;
- unsigned char __user *end;
- unsigned char val;
- int err;
+ unsigned char __user *addr = uaddr + expected_size;
+ int res;
if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
return -E2BIG;
- if (unlikely(!access_ok(uaddr, actual_size)))
- return -EFAULT;
-
if (actual_size <= expected_size)
return 0;
- addr = uaddr + expected_size;
- end = uaddr + actual_size;
-
- for (; addr < end; addr++) {
- err = get_user(val, addr);
- if (err)
- return err;
- if (val)
- return -E2BIG;
- }
-
- return 0;
+ res = check_zeroed_user(addr, actual_size - expected_size);
+ if (res < 0)
+ return res;
+ return res ? 0 : -E2BIG;
}
const struct bpf_map_ops bpf_map_offload_ops = {