From 2507135e4ff231a368eae38000a501da0b96c662 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 20 Jun 2023 11:30:36 -0600 Subject: [PATCH] readdir: Replace one-element arrays with flexible-array members 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 Reviewed-by: Kees Cook Message-Id: Signed-off-by: Christian Brauner --- 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 {