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Message-Id: <24e8d1d49af2664f945e7115de3dd0df2d6b5670.1580801787.git.christophe.leroy@c-s.fr>
Date: Tue, 4 Feb 2020 07:37:53 +0000 (UTC)
From: Christophe Leroy <christophe.leroy@....fr>
To: Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>
Cc: linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH 2/4] uaccess: Selectively open read or write user access
When opening user access to only perform reads, only open read access.
When opening user access to only perform writes, only open write
access.
Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
---
fs/readdir.c | 12 ++++++------
kernel/compat.c | 12 ++++++------
kernel/exit.c | 12 ++++++------
lib/strncpy_from_user.c | 4 ++--
lib/strnlen_user.c | 4 ++--
lib/usercopy.c | 6 +++---
6 files changed, 25 insertions(+), 25 deletions(-)
diff --git a/fs/readdir.c b/fs/readdir.c
index de2eceffdee8..ed6aaad451aa 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -242,7 +242,7 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen,
return -EINTR;
dirent = buf->current_dir;
prev = (void __user *) dirent - prev_reclen;
- if (!user_access_begin(prev, reclen + prev_reclen))
+ if (!user_write_access_begin(prev, reclen + prev_reclen))
goto efault;
/* This might be 'dirent->d_off', but if so it will get overwritten */
@@ -251,14 +251,14 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen,
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
- user_access_end();
+ user_write_access_end();
buf->current_dir = (void __user *)dirent + reclen;
buf->prev_reclen = reclen;
buf->count -= reclen;
return 0;
efault_end:
- user_access_end();
+ user_write_access_end();
efault:
buf->error = -EFAULT;
return -EFAULT;
@@ -327,7 +327,7 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
return -EINTR;
dirent = buf->current_dir;
prev = (void __user *)dirent - prev_reclen;
- if (!user_access_begin(prev, reclen + prev_reclen))
+ if (!user_write_access_begin(prev, reclen + prev_reclen))
goto efault;
/* This might be 'dirent->d_off', but if so it will get overwritten */
@@ -336,7 +336,7 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
unsafe_put_user(d_type, &dirent->d_type, efault_end);
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
- user_access_end();
+ user_write_access_end();
buf->prev_reclen = reclen;
buf->current_dir = (void __user *)dirent + reclen;
@@ -344,7 +344,7 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
return 0;
efault_end:
- user_access_end();
+ user_write_access_end();
efault:
buf->error = -EFAULT;
return -EFAULT;
diff --git a/kernel/compat.c b/kernel/compat.c
index 95005f849c68..7b8b59e039ba 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -263,7 +263,7 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!user_access_begin(umask, bitmap_size / 8))
+ if (!user_read_access_begin(umask, bitmap_size / 8))
return -EFAULT;
while (nr_compat_longs > 1) {
@@ -275,11 +275,11 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
}
if (nr_compat_longs)
unsafe_get_user(*mask, umask++, Efault);
- user_access_end();
+ user_read_access_end();
return 0;
Efault:
- user_access_end();
+ user_read_access_end();
return -EFAULT;
}
@@ -292,7 +292,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
- if (!user_access_begin(umask, bitmap_size / 8))
+ if (!user_write_access_begin(umask, bitmap_size / 8))
return -EFAULT;
while (nr_compat_longs > 1) {
@@ -303,10 +303,10 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
}
if (nr_compat_longs)
unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
- user_access_end();
+ user_write_access_end();
return 0;
Efault:
- user_access_end();
+ user_write_access_end();
return -EFAULT;
}
diff --git a/kernel/exit.c b/kernel/exit.c
index 2833ffb0c211..b33d3bcf9c9f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1563,7 +1563,7 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
if (!infop)
return err;
- if (!user_access_begin(infop, sizeof(*infop)))
+ if (!user_write_access_begin(infop, sizeof(*infop)))
return -EFAULT;
unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1572,10 +1572,10 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
unsafe_put_user(info.pid, &infop->si_pid, Efault);
unsafe_put_user(info.uid, &infop->si_uid, Efault);
unsafe_put_user(info.status, &infop->si_status, Efault);
- user_access_end();
+ user_write_access_end();
return err;
Efault:
- user_access_end();
+ user_write_access_end();
return -EFAULT;
}
@@ -1690,7 +1690,7 @@ COMPAT_SYSCALL_DEFINE5(waitid,
if (!infop)
return err;
- if (!user_access_begin(infop, sizeof(*infop)))
+ if (!user_write_access_begin(infop, sizeof(*infop)))
return -EFAULT;
unsafe_put_user(signo, &infop->si_signo, Efault);
@@ -1699,10 +1699,10 @@ COMPAT_SYSCALL_DEFINE5(waitid,
unsafe_put_user(info.pid, &infop->si_pid, Efault);
unsafe_put_user(info.uid, &infop->si_uid, Efault);
unsafe_put_user(info.status, &infop->si_status, Efault);
- user_access_end();
+ user_write_access_end();
return err;
Efault:
- user_access_end();
+ user_write_access_end();
return -EFAULT;
}
#endif
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 706020b06617..b90ec550183a 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -116,9 +116,9 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
kasan_check_write(dst, count);
check_object_size(dst, count, false);
- if (user_access_begin(src, max)) {
+ if (user_read_access_begin(src, max)) {
retval = do_strncpy_from_user(dst, src, count, max);
- user_access_end();
+ user_read_access_end();
return retval;
}
}
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 41670d4a5816..1616710b8a82 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -109,9 +109,9 @@ long strnlen_user(const char __user *str, long count)
if (max > count)
max = count;
- if (user_access_begin(str, max)) {
+ if (user_read_access_begin(str, max)) {
retval = do_strnlen_user(str, count, max);
- user_access_end();
+ user_read_access_end();
return retval;
}
}
diff --git a/lib/usercopy.c b/lib/usercopy.c
index cbb4d9ec00f2..ca2a697a2061 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -58,7 +58,7 @@ int check_zeroed_user(const void __user *from, size_t size)
from -= align;
size += align;
- if (!user_access_begin(from, size))
+ if (!user_read_access_begin(from, size))
return -EFAULT;
unsafe_get_user(val, (unsigned long __user *) from, err_fault);
@@ -79,10 +79,10 @@ int check_zeroed_user(const void __user *from, size_t size)
val &= aligned_byte_mask(size);
done:
- user_access_end();
+ user_read_access_end();
return (val == 0);
err_fault:
- user_access_end();
+ user_read_access_end();
return -EFAULT;
}
EXPORT_SYMBOL(check_zeroed_user);
--
2.25.0
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