From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4/oYbmf0esZfVKseTCx8eWqXPW/D3WxaqZjlqljccmU262z5YhNmN+QfY5M5TZLMmFb+G5n ARC-Seal: i=1; a=rsa-sha256; t=1523981072; cv=none; d=google.com; s=arc-20160816; b=qaQKtHQRN1kJ8nYKvmdaaMeo2KdsWeg50cP3zG///zbZbfKO81WJYzx1HNa7UqhZLE ok3Wws0TXYh+P/4jGawEuU7o1Mxy6Y7SNPMUY4Y3hE6MnNkJ1Bk7IqfykvvkLhSuie6B P96GkQcE1ABeNxwJI7V/X9W4icWxac9oBvqHF1qgnZiYcdDdeqnZSPE3C1XPtQsTnRRJ yXA32y5dDTpCjTAyhu/sqTvRjR+xC0pLhNY1ejH+lLdMZpmj160pektfH9yBNwVhpuWi ayT9LhNgoUc+7iGR2p7+U3/v4JmcfyTeqKysvS3TyQjBnkODTSbDnWzj37HOU8q+3HLE 23Yg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=HLwXOpXo28q8lqdJCz7eB2czef6OHbEmRDt+Jkc3glY=; b=RQr1yqpUxQsbmW/KFosHfV8tK7dyfo6EyXt58P0qGXof8Gyj5t2zhHiWawNRE3RB6p /Yloq9nxMC7GnT9qrbOGl5Qv0mqcDRwxyRjpwcywLqdXZI+kYMmd5GbEdn9Y4nXaqRte mhkWzzdUxQYNpM4iA2AlkDm+xy8RcoJ0c12QgRtzpcxGLd/Y2zn4d2O6zQmslxgoLa+D HCBCIVMie2hVVoP3MtlKwqL+fvWR2oR0Yp7GV1Y51JIhE6h7YIryCBS4pLWmUdiXb28F wOJuh4YXzBc1fnuVyT5W9Pk/sK4SsJBy525fQzlk4VmDeRtV9GaiOY9U3Cp0tYeUe8as 9sUQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 46.44.180.42 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 46.44.180.42 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yury Norov , Tetsuo Handa , syzbot , Noam Camus , Rasmus Villemoes , Matthew Wilcox , Mauro Carvalho Chehab , Andrew Morton , Linus Torvalds Subject: [PATCH 4.15 30/53] lib: fix stall in __bitmap_parselist() Date: Tue, 17 Apr 2018 17:58:55 +0200 Message-Id: <20180417155724.623157623@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180417155723.091120060@linuxfoundation.org> References: <20180417155723.091120060@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598009776446596481?= X-GMAIL-MSGID: =?utf-8?q?1598009977461684485?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yury Norov commit 8351760ff5b2042039554b4948ddabaac644a976 upstream. syzbot is catching stalls at __bitmap_parselist() (https://syzkaller.appspot.com/bug?id=ad7e0351fbc90535558514a71cd3edc11681997a). The trigger is unsigned long v = 0; bitmap_parselist("7:,", &v, BITS_PER_LONG); which results in hitting infinite loop at while (a <= b) { off = min(b - a + 1, used_size); bitmap_set(maskp, a, off); a += group_size; } due to used_size == group_size == 0. Link: http://lkml.kernel.org/r/20180404162647.15763-1-ynorov@caviumnetworks.com Fixes: 0a5ce0831d04382a ("lib/bitmap.c: make bitmap_parselist() thread-safe and much faster") Signed-off-by: Yury Norov Reported-by: Tetsuo Handa Reported-by: syzbot Cc: Noam Camus Cc: Rasmus Villemoes Cc: Matthew Wilcox Cc: Mauro Carvalho Chehab Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- lib/bitmap.c | 2 +- lib/test_bitmap.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -607,7 +607,7 @@ static int __bitmap_parselist(const char /* if no digit is after '-', it's wrong*/ if (at_start && in_range) return -EINVAL; - if (!(a <= b) || !(used_size <= group_size)) + if (!(a <= b) || group_size == 0 || !(used_size <= group_size)) return -EINVAL; if (b >= nmaskbits) return -ERANGE; --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -218,6 +218,10 @@ static const struct test_bitmap_parselis {-EINVAL, "-1", NULL, 8, 0}, {-EINVAL, "-0", NULL, 8, 0}, {-EINVAL, "10-1", NULL, 8, 0}, + {-EINVAL, "0-31:", NULL, 8, 0}, + {-EINVAL, "0-31:0", NULL, 8, 0}, + {-EINVAL, "0-31:0/0", NULL, 8, 0}, + {-EINVAL, "0-31:1/0", NULL, 8, 0}, {-EINVAL, "0-31:10/1", NULL, 8, 0}, };