Re: [PATCH net v3] net: cxgb4/ch_ipsec: fix potential use-after-free in ch_ipsec_xfrm_add_state() callback

[Jacob Keller]

On 10/13/2025 2:58 AM, Pavel Zhigulin wrote:
> In ch_ipsec_xfrm_add_state() there is not check of try_module_get
> return value. It is very unlikely, but try_module_get() could return
> false value, which could cause use-after-free error.
> Conditions: The module count must be zero, and a module unload in
> progress. The thread doing the unload is blocked somewhere.
> Another thread makes a callback into the module for some request
> that (for instance) would need to create a kernel thread.
> It tries to get a reference for the thread.
> So try_module_get(THIS_MODULE) is the right call - and will fail here.
> 
> This fix adds checking the result of try_module_get call
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 6dad4e8ab3ec ("chcr: Add support for Inline IPSec")
> Signed-off-by: Pavel Zhigulin <Pavel.Zhigulin@xxxxxxxxxxxxx>
> ---

Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>

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