From: Olivier Langlois <olivier@trillion01.com>
To: Jens Axboe <axboe@kernel.dk>,
Pavel Begunkov <asml.silence@gmail.com>,
Oleg Nesterov <oleg@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 3/3] coredump: cancel io_uring requests before dumping core
Date: Sun, 22 Aug 2021 17:06:06 -0400 [thread overview]
Message-ID: <1625bc89782bf83d9d8c7c63e8ffcb651ccb15fa.1629655338.git.olivier@trillion01.com> (raw)
In-Reply-To: <cover.1629655338.git.olivier@trillion01.com>
The previous solution of ignoring the TIF_NOTIFY_SIGNAL bit while
dumping core is only working when the core dump is sent in a file.
When a pipe is used, pipe_write returns -ERESTARTSYS if signal_pending
which includes TIF_NOTIFY_SIGNAL is true.
A more robust solution is to make sure that io_uring will not set
TIF_NOTIFY_SIGNAL while the core dump is generated by cancelling all
the io_uring requests made by the current task before starting.
Fixes: 06af8679449d ("coredump: Limit what can interrupt coredumps")
Signed-off-by: Olivier Langlois <olivier@trillion01.com>
---
fs/coredump.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/coredump.c b/fs/coredump.c
index 07afb5ddb1c4..9aceb4b3b40d 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -41,6 +41,7 @@
#include <linux/fs.h>
#include <linux/path.h>
#include <linux/timekeeping.h>
+#include <linux/io_uring.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
@@ -625,6 +626,8 @@ void do_coredump(const kernel_siginfo_t *siginfo)
need_suid_safe = true;
}
+ io_uring_task_cancel();
+
retval = coredump_wait(siginfo->si_signo, &core_state);
if (retval < 0)
goto fail_creds;
--
2.32.0
prev parent reply other threads:[~2021-08-22 21:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-22 21:05 [PATCH 0/3] coredump: io_uring: Cancel io_uring to avoid core truncation Olivier Langlois
2021-08-22 21:05 ` [PATCH 1/3] tracehook: Add a return value to tracehook_notify_signal Olivier Langlois
2021-08-22 21:05 ` [PATCH 2/3] io_uring: Clear TIF_NOTIFY_SIGNAL when cancelling requests Olivier Langlois
2021-08-22 21:06 ` Olivier Langlois [this message]
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