Messages in this thread Patch in this message |  | | From | Christophe Leroy <> | Subject | [PATCH 2/4] uaccess: Selectively open read or write user access | Date | Tue, 4 Feb 2020 07:37:53 +0000 (UTC) |
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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@c-s.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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