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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-04-03 07:20:51 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-01 12:35:21 +1000 |
| commit | 41cd780524674082b037e7c8461f90c5e42103f0 (patch) | |
| tree | eb705efdf71be777efedd2cd76e1f47d7cd753e2 /fs/readdir.c | |
| parent | 999a22890cb183b918e4372395d24426a755cef2 (diff) | |
| download | lwn-41cd780524674082b037e7c8461f90c5e42103f0.tar.gz lwn-41cd780524674082b037e7c8461f90c5e42103f0.zip | |
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@c-s.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2e73bc57125c2c6ab12a587586a4eed3a47105fc.1585898438.git.christophe.leroy@c-s.fr
Diffstat (limited to 'fs/readdir.c')
| -rw-r--r-- | fs/readdir.c | 12 |
1 files changed, 6 insertions, 6 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; |