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ncpfs: don't allow negative timeouts

PATCH Superseded Dan Carpenter 2 participants 4 messages Nov 10, 2015 – Nov 11, 2015 Kernel janitors

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Dan Carpenter

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#0 lore raw

PATCH 1/1 ncpfs: don't allow negative timeouts

This code causes a static checker warning because it's a user controlled variable where we cap the upper bound but not the lower bound. If someone passes us a negative timeout then I guess lets set it to the default.

Signed-off-by Dan Carpenter <[email protected]>
fs/ncpfs/ioctl.c +1 -1
index 79b1130..c07498a 100644
@@ -525,7 +525,7 @@ static long __ncp_ioctl(struct inode *inode, unsigned int cmd, unsigned long arg
 			switch (rqdata.cmd) {
 				case NCP_LOCK_EX:
 				case NCP_LOCK_SH:
-						if (rqdata.timeout = 0)
+						if (rqdata.timeout <= 0)
 							rqdata.timeout = NCP_LOCK_DEFAULT_TIMEOUT;
 						else if (rqdata.timeout > NCP_LOCK_MAX_TIMEOUT)
 							rqdata.timeout = NCP_LOCK_MAX_TIMEOUT;
#1 lore raw
Quoted 6 lines · Dan Carpenter

This code causes a static checker warning because it's a user controlled variable where we cap the upper bound but not the lower bound. If someone passes us a negative timeout then I guess lets set it to the default.

Signed-off-by Dan Carpenter <[email protected]>

IMHO it would be better to return error from the ioctl. Currently it would just wrap when converting to u16 anyway...

Honza

Quoted 14 lines
fs/ncpfs/ioctl.c +1 -1
index 79b1130..c07498a 100644
@@ -525,7 +525,7 @@ static long __ncp_ioctl(struct inode *inode, unsigned int cmd, unsigned long arg
 			switch (rqdata.cmd) {
 				case NCP_LOCK_EX:
 				case NCP_LOCK_SH:
-						if (rqdata.timeout = 0)
+						if (rqdata.timeout <= 0)
 							rqdata.timeout = NCP_LOCK_DEFAULT_TIMEOUT;
 						else if (rqdata.timeout > NCP_LOCK_MAX_TIMEOUT)
 							rqdata.timeout = NCP_LOCK_MAX_TIMEOUT;
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#2 lore raw

PATCH v2 1/1 ncpfs: don't allow negative timeouts

This code causes a static checker warning because it's a user controlled variable where we cap the upper bound but not the lower bound. Let's return an -EINVAL for negative timeouts.

Signed-off-by Dan Carpenter <[email protected]>

---
v2: in the original I just ignored the invalid data and went with the
default but now it returns -EINVAL.

fs/ncpfs/ioctl.c +3 -1
index 79b1130..ebf45d2 100644
@@ -525,7 +525,9 @@ static long __ncp_ioctl(struct inode *inode, unsigned int cmd, unsigned long arg
 			switch (rqdata.cmd) {
 				case NCP_LOCK_EX:
 				case NCP_LOCK_SH:
-						if (rqdata.timeout = 0)
+						if (rqdata.timeout < 0)
+							return -EINVAL;
+						else if (rqdata.timeout = 0)
 							rqdata.timeout = NCP_LOCK_DEFAULT_TIMEOUT;
 						else if (rqdata.timeout > NCP_LOCK_MAX_TIMEOUT)
 							rqdata.timeout = NCP_LOCK_MAX_TIMEOUT;
Reviewed-by on v2 1/1
#3 lore raw
Quoted 5 lines · Dan Carpenter

This code causes a static checker warning because it's a user controlled variable where we cap the upper bound but not the lower bound. Let's return an -EINVAL for negative timeouts.

Signed-off-by Dan Carpenter <[email protected]>

Looks good. You can add:

Reviewed-by Jan Kara <[email protected]>

Honza

Quoted 19 lines

---
v2: in the original I just ignored the invalid data and went with the
default but now it returns -EINVAL.

fs/ncpfs/ioctl.c +3 -1
index 79b1130..ebf45d2 100644
@@ -525,7 +525,9 @@ static long __ncp_ioctl(struct inode *inode, unsigned int cmd, unsigned long arg
 			switch (rqdata.cmd) {
 				case NCP_LOCK_EX:
 				case NCP_LOCK_SH:
-						if (rqdata.timeout = 0)
+						if (rqdata.timeout < 0)
+							return -EINVAL;
+						else if (rqdata.timeout = 0)
 							rqdata.timeout = NCP_LOCK_DEFAULT_TIMEOUT;
 						else if (rqdata.timeout > NCP_LOCK_MAX_TIMEOUT)
 							rqdata.timeout = NCP_LOCK_MAX_TIMEOUT;
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR