diff mbox series

[net] net: phy: fix phy_read_poll_timeout argument type in genphy_loopback

Message ID 20240315175052.8049-1-kiryushin@ancud.ru (mailing list archive)
State Accepted
Commit 32fa4366cc4da1c97b725a0066adf43c6b298f37
Delegated to: Netdev Maintainers
Headers show
Series [net] net: phy: fix phy_read_poll_timeout argument type in genphy_loopback | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 939 this patch: 939
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 956 this patch: 956
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 956 this patch: 956
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 10 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-03-15--21-00 (tests: 903)

Commit Message

Nikita Kiryushin March 15, 2024, 5:50 p.m. UTC
read_poll_timeout inside phy_read_poll_timeout can set val negative
in some cases (for example, __mdiobus_read inside phy_read can return
-EOPNOTSUPP).

Supposedly, commit 4ec732951702 ("net: phylib: fix phy_read*_poll_timeout()")
should fix problems with wrong-signed vals, but I do not see how
as val is sent to phy_read as is and __val = phy_read (not val)
is checked for sign.

Change val type for signed to allow better error handling as done in other
phy_read_poll_timeout callers. This will not fix any error handling
by itself, but allows, for example, to modify cond with appropriate
sign check or check resulting val separately.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
---
 drivers/net/phy/phy_device.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Russell King (Oracle) March 15, 2024, 6:38 p.m. UTC | #1
On Fri, Mar 15, 2024 at 08:50:52PM +0300, Nikita Kiryushin wrote:
> read_poll_timeout inside phy_read_poll_timeout can set val negative
> in some cases (for example, __mdiobus_read inside phy_read can return
> -EOPNOTSUPP).
> 
> Supposedly, commit 4ec732951702 ("net: phylib: fix phy_read*_poll_timeout()")
> should fix problems with wrong-signed vals, but I do not see how
> as val is sent to phy_read as is and __val = phy_read (not val)
> is checked for sign.
> 
> Change val type for signed to allow better error handling as done in other
> phy_read_poll_timeout callers. This will not fix any error handling
> by itself, but allows, for example, to modify cond with appropriate
> sign check or check resulting val separately.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration")
> Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Thanks!
patchwork-bot+netdevbpf@kernel.org March 19, 2024, 3:20 p.m. UTC | #2
Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Fri, 15 Mar 2024 20:50:52 +0300 you wrote:
> read_poll_timeout inside phy_read_poll_timeout can set val negative
> in some cases (for example, __mdiobus_read inside phy_read can return
> -EOPNOTSUPP).
> 
> Supposedly, commit 4ec732951702 ("net: phylib: fix phy_read*_poll_timeout()")
> should fix problems with wrong-signed vals, but I do not see how
> as val is sent to phy_read as is and __val = phy_read (not val)
> is checked for sign.
> 
> [...]

Here is the summary with links:
  - [net] net: phy: fix phy_read_poll_timeout argument type in genphy_loopback
    https://git.kernel.org/netdev/net/c/32fa4366cc4d

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8297ef681bf5..6c6ec9475709 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2831,8 +2831,8 @@  EXPORT_SYMBOL(genphy_resume);
 int genphy_loopback(struct phy_device *phydev, bool enable)
 {
 	if (enable) {
-		u16 val, ctl = BMCR_LOOPBACK;
-		int ret;
+		u16 ctl = BMCR_LOOPBACK;
+		int ret, val;
 
 		ctl |= mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);