From 95c5f43181fe9c1b5e5a4bd3281c857a5259991f Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 14 Apr 2025 15:55:06 +0200 Subject: [PATCH] coredump: fix error handling for replace_fd() The replace_fd() helper returns the file descriptor number on success and a negative error code on failure. The current error handling in umh_pipe_setup() only works because the file descriptor that is replaced is zero but that's pretty volatile. Explicitly check for a negative error code. Link: https://lore.kernel.org/20250414-work-coredump-v2-2-685bf231f828@kernel.org Tested-by: Luca Boccassi Reviewed-by: Oleg Nesterov Signed-off-by: Christian Brauner --- fs/coredump.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/coredump.c b/fs/coredump.c index c33c177a701b..9da592aa8f16 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -507,7 +507,9 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) { struct file *files[2]; struct coredump_params *cp = (struct coredump_params *)info->data; - int err = create_pipe_files(files, 0); + int err; + + err = create_pipe_files(files, 0); if (err) return err; @@ -515,10 +517,13 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) err = replace_fd(0, files[0], 0); fput(files[0]); + if (err < 0) + return err; + /* and disallow core files too */ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; - return err; + return 0; } void do_coredump(const kernel_siginfo_t *siginfo) -- 2.50.1