lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <YxBj0QAdRaVZCr9i@gondor.apana.org.au> Date: Thu, 1 Sep 2022 15:48:33 +0800 From: Herbert Xu <herbert@...dor.apana.org.au> To: Khalid Masum <khalid.masum.92@...il.com> Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com, Steffen Klassert <steffen.klassert@...unet.com>, "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, linux-kernel-mentees@...ts.linuxfoundation.org, Shuah Khan <skhan@...uxfoundation.org>, syzbot+5ec9bb042ddfe9644773@...kaller.appspotmail.com Subject: Re: [PATCH v4] xfrm: Update ipcomp_scratches with NULL when freed On Thu, Sep 01, 2022 at 01:12:10PM +0600, Khalid Masum wrote: > Currently if ipcomp_alloc_scratches() fails to allocate memory > ipcomp_scratches holds obsolete address. So when we try to free the > percpu scratches using ipcomp_free_scratches() it tries to vfree non > existent vm area. Described below: > > static void * __percpu *ipcomp_alloc_scratches(void) > { > ... > scratches = alloc_percpu(void *); > if (!scratches) > return NULL; > ipcomp_scratches does not know about this allocation failure. > Therefore holding the old obsolete address. > ... > } > > So when we free, > > static void ipcomp_free_scratches(void) > { > ... > scratches = ipcomp_scratches; > Assigning obsolete address from ipcomp_scratches > > if (!scratches) > return; > > for_each_possible_cpu(i) > vfree(*per_cpu_ptr(scratches, i)); > Trying to free non existent page, causing warning: trying to vfree > existent vm area. > ... > } > > Fix this breakage by updating ipcomp_scrtches with NULL when scratches > is freed > > Suggested-by: Herbert Xu <herbert@...dor.apana.org.au> > Reported-by: syzbot+5ec9bb042ddfe9644773@...kaller.appspotmail.com > Tested-by: syzbot+5ec9bb042ddfe9644773@...kaller.appspotmail.com > Signed-off-by: Khalid Masum <khalid.masum.92@...il.com> Acked-by: Herbert Xu <herbert@...dor.apana.org.au> Thanks, -- Email: Herbert Xu <herbert@...dor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
Powered by blists - more mailing lists