Bug 2486456 (CVE-2026-46307)

Summary: CVE-2026-46307 kernel: wifi: ath5k: do not access array OOB
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's ath5k Wi-Fi driver. This vulnerability allows for an array-index-out-of-bounds write in the `ath5k_tasklet_tx` function. An attacker could potentially trigger this by manipulating specific index values, leading to a minor data corruption. The immediate impact of this out-of-bounds write is considered negligible, affecting only the `ack_signal` member of the `info->status` structure.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-06-08 17:02:56 UTC
In the Linux kernel, the following vulnerability has been resolved:

wifi: ath5k: do not access array OOB

Vincent reports:
> The ath5k driver seems to do an array-index-out-of-bounds access as
> shown by the UBSAN kernel message:
> UBSAN: array-index-out-of-bounds in drivers/net/wireless/ath/ath5k/base.c:1741:20
> index 4 is out of range for type 'ieee80211_tx_rate [4]'
> ...
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x5d/0x80
>  ubsan_epilogue+0x5/0x2b
>  __ubsan_handle_out_of_bounds.cold+0x46/0x4b
>  ath5k_tasklet_tx+0x4e0/0x560 [ath5k]
>  tasklet_action_common+0xb5/0x1c0

It is real. 'ts->ts_final_idx' can be 3 on 5212, so:
   info->status.rates[ts->ts_final_idx + 1].idx = -1;
with the array defined as:
   struct ieee80211_tx_rate rates[IEEE80211_TX_MAX_RATES];
while the size is:
   #define IEEE80211_TX_MAX_RATES  4
is indeed bogus.

Set this 'idx = -1' sentinel only if the array index is less than the
array size. As mac80211 will not look at rates beyond the size
(IEEE80211_TX_MAX_RATES).

Note: The effect of the OOB write is negligible. It just overwrites the
next member of info->status, i.e. ack_signal.