linux-kernel - [PATCH v3 06/11] kgdb: Prevent infinite recursive entries to the debugger

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 28 Apr 2020 14:13:46 -0700
From:   Douglas Anderson <dianders@...omium.org>
To:     jason.wessel@...driver.com, daniel.thompson@...aro.org,
        gregkh@...uxfoundation.org
Cc:     agross@...nel.org, kgdb-bugreport@...ts.sourceforge.net,
        catalin.marinas@....com, linux-serial@...r.kernel.org,
        sumit.garg@...aro.org, corbet@....net, mingo@...hat.com,
        will@...nel.org, hpa@...or.com, tglx@...utronix.de,
        frowand.list@...il.com, bp@...en8.de, bjorn.andersson@...aro.org,
        jslaby@...e.com, Douglas Anderson <dianders@...omium.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 06/11] kgdb: Prevent infinite recursive entries to the debugger

If we detect that we recursively entered the debugger we should hack
our I/O ops to NULL so that the panic() in the next line won't
actually cause another recursion into the debugger.  The first line of
kgdb_panic() will check this and return.

Signed-off-by: Douglas Anderson <dianders@...omium.org>
---

Changes in v3:
- ("kgdb: Prevent infinite recursive entries to the debugger") new for v3.

Changes in v2: None

 kernel/debug/debug_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 503c1630ca76..faf5bd4c34ee 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -532,6 +532,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
 
 	if (exception_level > 1) {
 		dump_stack();
+		kgdb_io_module_registered = false;
 		panic("Recursive entry to debugger");
 	}
 
-- 
2.26.2.303.gf8c07b1a785-goog