| Message ID | 1717771212-30723-2-git-send-email-quic_zijuhu@quicinc.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | net: rfkill: Fix 2 bugs within rfkill_set_hw_state_reason() | expand |
> > use pr_err() instead of WARN() > for this error case handling. I don't see anything wrong with the WARN here, it's the user/driver calling it completely incorrectly. I also don't really think this is a *fix*, if you used the API incorrectly you can't necessarily expect a correct return value, I guess, but anyway it shouldn't happen in the first place. I'm happy to take the return value change (only) as a cleanup, if you wish to resend that. > Fixed by Please also read https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches johannes
On 6/12/2024 4:15 PM, Johannes Berg wrote: >> >> use pr_err() instead of WARN() >> for this error case handling. > > I don't see anything wrong with the WARN here, it's the user/driver > calling it completely incorrectly. > the function is a kernel API and it is handing invalid user input. below comments for WARN() seems say that pr_err() is better than WARN() for this case. include/asm-generic/bug.h: /* * WARN(), WARN_ON(), WARN_ON_ONCE(), and so on can be used to report * significant kernel issues that need prompt attention if they should ever * appear at runtime. * * Do not use these macros when checking for invalid external inputs * (e.g. invalid system call arguments, or invalid data coming from * network/devices), and on transient conditions like ENOMEM or EAGAIN. * These macros should be used for recoverable kernel issues only. * For invalid external inputs, transient conditions, etc use * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary. * Do not include "BUG"/"WARNING" in format strings manually to make these * conditions distinguishable from kernel issues. * * Use the versions with printk format strings to provide better diagnostics. */ > I also don't really think this is a *fix*, if you used the API > incorrectly you can't necessarily expect a correct return value, I > guess, but anyway it shouldn't happen in the first place. > okay, will remove term fix and fix tag. the API returns type bool for block state, the type bool can't cover case for invalid user input. > I'm happy to take the return value change (only) as a cleanup, if you > wish to resend that. > i am pleasure to resend it after code review done. >> Fixed by > > Please also read > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches > okay, thank you > johannes
On Wed, 2024-06-12 at 18:12 +0800, quic_zijuhu wrote: > On 6/12/2024 4:15 PM, Johannes Berg wrote: > > > > > > use pr_err() instead of WARN() > > > for this error case handling. > > > > I don't see anything wrong with the WARN here, it's the user/driver > > calling it completely incorrectly. > > > the function is a kernel API Sure. > and it is handing invalid user input. No. johannes
diff --git a/net/rfkill/core.c b/net/rfkill/core.c index c3feb4f49d09..0dc982b4fce6 100644 --- a/net/rfkill/core.c +++ b/net/rfkill/core.c @@ -543,13 +543,15 @@ bool rfkill_set_hw_state_reason(struct rfkill *rfkill, { unsigned long flags; bool ret, prev; + const unsigned long reason_mask = RFKILL_HARD_BLOCK_SIGNAL | + RFKILL_HARD_BLOCK_NOT_OWNER; BUG_ON(!rfkill); - if (WARN(reason & - ~(RFKILL_HARD_BLOCK_SIGNAL | RFKILL_HARD_BLOCK_NOT_OWNER), - "hw_state reason not supported: 0x%lx", reason)) - return blocked; + if (reason & ~reason_mask) { + pr_err("hw_state reason not supported: 0x%lx\n", reason); + return rfkill_blocked(rfkill); + } spin_lock_irqsave(&rfkill->lock, flags); prev = !!(rfkill->hard_block_reasons & reason);
Kernel API rfkill_set_hw_state_reason() does not return current combined block state when its parameter @reason is invalid, that is wrong according to its comments. Fixed by returning API required value, also use pr_err() instead of WARN() for this error case handling. Fixes: 14486c82612a ("rfkill: add a reason to the HW rfkill state") Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> --- net/rfkill/core.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)