5.4-stable review patch. If anyone has any objections, please let me know.
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From: Christian Brauner brauner@kernel.org
commit 95c5f43181fe9c1b5e5a4bd3281c857a5259991f upstream.
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 luca.boccassi@gmail.com Reviewed-by: Oleg Nesterov oleg@redhat.com Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/coredump.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/fs/coredump.c +++ b/fs/coredump.c @@ -551,7 +551,9 @@ static int umh_pipe_setup(struct subproc { 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;
@@ -559,10 +561,13 @@ static int umh_pipe_setup(struct subproc
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)