Re: [syzbot] [crypto?] KMSAN: uninit-value in af_alg_free_resources

[Pavel Skripkin <paskripkin@gmail.com>]

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Hi Syzbot,

Syzbot <syzbot+cba21d50095623218389@syzkaller.appspotmail.com> says:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    3f01e9fed845 Merge tag 'linux-watchdog-6.5-rc2' of git://w..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=14bac16aa80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=1542573e31cfbec5
> dashboard link: https://syzkaller.appspot.com/bug?extid=cba21d50095623218389
> compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15dd215aa80000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14530318a80000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/4f212a7e36fe/disk-3f01e9fe.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/de6b12daf908/vmlinux-3f01e9fe.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2c1992ff2aaa/bzImage-3f01e9fe.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+cba21d50095623218389@syzkaller.appspotmail.com

#syz test
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master





With regards,
Pavel Skripkin

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diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 06b15b9f661c..4e4f2d837481 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -1241,6 +1241,8 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
 				return -ENOMEM;
 		}
 
+		rsgl->sgl.need_unpin = 0;
+
 		rsgl->sgl.sgt.sgl = rsgl->sgl.sgl;
 		rsgl->sgl.sgt.nents = 0;
 		rsgl->sgl.sgt.orig_nents = 0;