From: Dmitry Antipov dmantipov@yandex.ru
[ Upstream commit 0015eb6e12384ff1c589928e84deac2ad1ceb236 ]
When compiling with gcc version 14.0.0 20231126 (experimental) and CONFIG_FORTIFY_SOURCE=y, I've noticed the following:
In file included from ./include/linux/string.h:295, from ./include/linux/bitmap.h:12, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/paravirt.h:17, from ./arch/x86/include/asm/cpuid.h:62, from ./arch/x86/include/asm/processor.h:19, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:79, from ./include/linux/spinlock.h:56, from ./include/linux/wait.h:9, from ./include/linux/wait_bit.h:8, from ./include/linux/fs.h:6, from fs/smb/client/smb2pdu.c:18: In function 'fortify_memcpy_chk', inlined from '__SMB2_close' at fs/smb/client/smb2pdu.c:3480:4: ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 588 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and:
In file included from ./include/linux/string.h:295, from ./include/linux/bitmap.h:12, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/paravirt.h:17, from ./arch/x86/include/asm/cpuid.h:62, from ./arch/x86/include/asm/processor.h:19, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:79, from ./include/linux/spinlock.h:56, from ./include/linux/wait.h:9, from ./include/linux/wait_bit.h:8, from ./include/linux/fs.h:6, from fs/smb/client/cifssmb.c:17: In function 'fortify_memcpy_chk', inlined from 'CIFS_open' at fs/smb/client/cifssmb.c:1248:3: ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 588 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In both cases, the fortification logic inteprets calls to 'memcpy()' as an attempts to copy an amount of data which exceeds the size of the specified field (i.e. more than 8 bytes from __le64 value) and thus issues an overread warning. Both of these warnings may be silenced by using the convenient 'struct_group()' quirk.
Signed-off-by: Dmitry Antipov dmantipov@yandex.ru Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifspdu.h | 24 ++++++++++++++---------- fs/smb/client/cifssmb.c | 6 ++++-- fs/smb/client/smb2pdu.c | 8 +++----- fs/smb/client/smb2pdu.h | 16 +++++++++------- fs/smb/common/smb2pdu.h | 17 ++++++++++------- 5 files changed, 40 insertions(+), 31 deletions(-)
diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h index a75220db5c1e1..11081492d9436 100644 --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/cifspdu.h @@ -882,11 +882,13 @@ typedef struct smb_com_open_rsp { __u8 OplockLevel; __u16 Fid; __le32 CreateAction; - __le64 CreationTime; - __le64 LastAccessTime; - __le64 LastWriteTime; - __le64 ChangeTime; - __le32 FileAttributes; + struct_group(common_attributes, + __le64 CreationTime; + __le64 LastAccessTime; + __le64 LastWriteTime; + __le64 ChangeTime; + __le32 FileAttributes; + ); __le64 AllocationSize; __le64 EndOfFile; __le16 FileType; @@ -2264,11 +2266,13 @@ typedef struct { /* QueryFileInfo/QueryPathinfo (also for SetPath/SetFile) data buffer formats */ /******************************************************************************/ typedef struct { /* data block encoding of response to level 263 QPathInfo */ - __le64 CreationTime; - __le64 LastAccessTime; - __le64 LastWriteTime; - __le64 ChangeTime; - __le32 Attributes; + struct_group(common_attributes, + __le64 CreationTime; + __le64 LastAccessTime; + __le64 LastWriteTime; + __le64 ChangeTime; + __le32 Attributes; + ); __u32 Pad1; __le64 AllocationSize; __le64 EndOfFile; /* size ie offset to first free byte in file */ diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 25503f1a4fd21..09e66ceb38a25 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -1244,8 +1244,10 @@ CIFS_open(const unsigned int xid, struct cifs_open_parms *oparms, int *oplock, *oplock |= CIFS_CREATE_ACTION;
if (buf) { - /* copy from CreationTime to Attributes */ - memcpy((char *)buf, (char *)&rsp->CreationTime, 36); + /* copy commonly used attributes */ + memcpy(&buf->common_attributes, + &rsp->common_attributes, + sizeof(buf->common_attributes)); /* the file_info buf is endian converted by caller */ buf->AllocationSize = rsp->AllocationSize; buf->EndOfFile = rsp->EndOfFile; diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index c75a80bb6d9ee..3e388c6cb5c25 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -3377,12 +3377,10 @@ __SMB2_close(const unsigned int xid, struct cifs_tcon *tcon, } else { trace_smb3_close_done(xid, persistent_fid, tcon->tid, ses->Suid); - /* - * Note that have to subtract 4 since struct network_open_info - * has a final 4 byte pad that close response does not have - */ if (pbuf) - memcpy(pbuf, (char *)&rsp->CreationTime, sizeof(*pbuf) - 4); + memcpy(&pbuf->network_open_info, + &rsp->network_open_info, + sizeof(pbuf->network_open_info)); }
atomic_dec(&tcon->num_remote_opens); diff --git a/fs/smb/client/smb2pdu.h b/fs/smb/client/smb2pdu.h index 220994d0a0f7f..db08194484e06 100644 --- a/fs/smb/client/smb2pdu.h +++ b/fs/smb/client/smb2pdu.h @@ -319,13 +319,15 @@ struct smb2_file_reparse_point_info { } __packed;
struct smb2_file_network_open_info { - __le64 CreationTime; - __le64 LastAccessTime; - __le64 LastWriteTime; - __le64 ChangeTime; - __le64 AllocationSize; - __le64 EndOfFile; - __le32 Attributes; + struct_group(network_open_info, + __le64 CreationTime; + __le64 LastAccessTime; + __le64 LastWriteTime; + __le64 ChangeTime; + __le64 AllocationSize; + __le64 EndOfFile; + __le32 Attributes; + ); __le32 Reserved; } __packed; /* level 34 Query also similar returned in close rsp and open rsp */
diff --git a/fs/smb/common/smb2pdu.h b/fs/smb/common/smb2pdu.h index 319fb9ffc6a03..7d676e7fa5b1a 100644 --- a/fs/smb/common/smb2pdu.h +++ b/fs/smb/common/smb2pdu.h @@ -700,13 +700,16 @@ struct smb2_close_rsp { __le16 StructureSize; /* 60 */ __le16 Flags; __le32 Reserved; - __le64 CreationTime; - __le64 LastAccessTime; - __le64 LastWriteTime; - __le64 ChangeTime; - __le64 AllocationSize; /* Beginning of FILE_STANDARD_INFO equivalent */ - __le64 EndOfFile; - __le32 Attributes; + struct_group(network_open_info, + __le64 CreationTime; + __le64 LastAccessTime; + __le64 LastWriteTime; + __le64 ChangeTime; + /* Beginning of FILE_STANDARD_INFO equivalent */ + __le64 AllocationSize; + __le64 EndOfFile; + __le32 Attributes; + ); } __packed;