fs/readdir.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element arrays with flexible-array
members in multiple structures.
Address the following -Wstringop-overflow warnings seen when built
m68k architecture with m5307c3_defconfig configuration:
In function '__put_user_fn',
inlined from 'fillonedir' at fs/readdir.c:170:2:
include/asm-generic/uaccess.h:49:35: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
49 | *(u8 __force *)to = *(u8 *)from;
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
fs/readdir.c: In function 'fillonedir':
fs/readdir.c:134:25: note: at offset 1 into destination object 'd_name' of size 1
134 | char d_name[1];
| ^~~~~~
In function '__put_user_fn',
inlined from 'filldir' at fs/readdir.c:257:2:
include/asm-generic/uaccess.h:49:35: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
49 | *(u8 __force *)to = *(u8 *)from;
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
fs/readdir.c: In function 'filldir':
fs/readdir.c:211:25: note: at offset 1 into destination object 'd_name' of size 1
211 | char d_name[1];
| ^~~~~~
This helps with the ongoing efforts to globally enable
-Wstringop-overflow.
This results in no differences in binary output.
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/312
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
fs/readdir.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/readdir.c b/fs/readdir.c
index 9c53edb60c03..b264ce60114d 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -131,7 +131,7 @@ struct old_linux_dirent {
unsigned long d_ino;
unsigned long d_offset;
unsigned short d_namlen;
- char d_name[1];
+ char d_name[];
};
struct readdir_callback {
@@ -208,7 +208,7 @@ struct linux_dirent {
unsigned long d_ino;
unsigned long d_off;
unsigned short d_reclen;
- char d_name[1];
+ char d_name[];
};
struct getdents_callback {
@@ -388,7 +388,7 @@ struct compat_old_linux_dirent {
compat_ulong_t d_ino;
compat_ulong_t d_offset;
unsigned short d_namlen;
- char d_name[1];
+ char d_name[];
};
struct compat_readdir_callback {
@@ -460,7 +460,7 @@ struct compat_linux_dirent {
compat_ulong_t d_ino;
compat_ulong_t d_off;
unsigned short d_reclen;
- char d_name[1];
+ char d_name[];
};
struct compat_getdents_callback {
--
2.34.1On Tue, 20 Jun 2023 11:30:36 -0600, Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element arrays with flexible-array
> members in multiple structures.
>
> Address the following -Wstringop-overflow warnings seen when built
> m68k architecture with m5307c3_defconfig configuration:
> In function '__put_user_fn',
> inlined from 'fillonedir' at fs/readdir.c:170:2:
> include/asm-generic/uaccess.h:49:35: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
> 49 | *(u8 __force *)to = *(u8 *)from;
> | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
> fs/readdir.c: In function 'fillonedir':
> fs/readdir.c:134:25: note: at offset 1 into destination object 'd_name' of size 1
> 134 | char d_name[1];
> | ^~~~~~
> In function '__put_user_fn',
> inlined from 'filldir' at fs/readdir.c:257:2:
> include/asm-generic/uaccess.h:49:35: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
> 49 | *(u8 __force *)to = *(u8 *)from;
> | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
> fs/readdir.c: In function 'filldir':
> fs/readdir.c:211:25: note: at offset 1 into destination object 'd_name' of size 1
> 211 | char d_name[1];
> | ^~~~~~
>
> [...]
Applied to the vfs.misc branch of the vfs/vfs.git tree.
Patches in the vfs.misc branch should appear in linux-next soon.
Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.
It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.misc
[1/1] readdir: Replace one-element arrays with flexible-array members
https://git.kernel.org/vfs/vfs/c/2507135e4ff2
On Tue, Jun 20, 2023 at 11:30:36AM -0600, Gustavo A. R. Silva wrote: > One-element arrays are deprecated, and we are replacing them with flexible > array members instead. So, replace one-element arrays with flexible-array > members in multiple structures. > > Address the following -Wstringop-overflow warnings seen when built > m68k architecture with m5307c3_defconfig configuration: > In function '__put_user_fn', > inlined from 'fillonedir' at fs/readdir.c:170:2: > include/asm-generic/uaccess.h:49:35: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] > 49 | *(u8 __force *)to = *(u8 *)from; > | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ > fs/readdir.c: In function 'fillonedir': > fs/readdir.c:134:25: note: at offset 1 into destination object 'd_name' of size 1 > 134 | char d_name[1]; > | ^~~~~~ > In function '__put_user_fn', > inlined from 'filldir' at fs/readdir.c:257:2: > include/asm-generic/uaccess.h:49:35: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] > 49 | *(u8 __force *)to = *(u8 *)from; > | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ > fs/readdir.c: In function 'filldir': > fs/readdir.c:211:25: note: at offset 1 into destination object 'd_name' of size 1 > 211 | char d_name[1]; > | ^~~~~~ > > This helps with the ongoing efforts to globally enable > -Wstringop-overflow. > > This results in no differences in binary output. > > Link: https://github.com/KSPP/linux/issues/79 > Link: https://github.com/KSPP/linux/issues/312 > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks! We're getting closer every day to killing this code pattern for good. :) Reviewed-by: Kees Cook <keescook@chromium.org> -- Kees Cook
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