From: Andrei Tatar <andrei@unikraft.io>
Date: Tue, 18 Mar 2025 16:48:20 +0000 (+0100)
Subject: lib/posix-fdio: Fix missing error in fcntl(GETFD)
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=ebcfc3cc62d70956ba91946189cd7c41ebc1d764;p=unikraft%2Funikraft.git

lib/posix-fdio: Fix missing error in fcntl(GETFD)

This change fixes a bug where fcntl(F_GETFD) would swallow error codes
from uk_fdtab_getflags and not return them up the callstack.

Signed-off-by: Andrei Tatar <andrei@unikraft.io>
Approved-by: Sergiu Moga <sergiu@unikraft.io>
Reviewed-by: Sergiu Moga <sergiu@unikraft.io>
GitHub-Closes: #1602
---

diff --git a/lib/posix-fdio/fd-shim.c b/lib/posix-fdio/fd-shim.c
index 7fb073308..687dfcb03 100644
--- a/lib/posix-fdio/fd-shim.c
+++ b/lib/posix-fdio/fd-shim.c
@@ -499,7 +499,10 @@ UK_LLSYSCALL_R_DEFINE(int, fcntl, int, fd,
 	case F_DUPFD:
 		return uk_sys_dup_min(fd, (int)arg, fdflags);
 	case F_GETFD:
-		return (uk_fdtab_getflags(fd) & O_CLOEXEC) ? FD_CLOEXEC : 0;
+		fdflags = uk_fdtab_getflags(fd);
+		if (unlikely(fdflags < 0))
+			return fdflags;
+		return (fdflags & O_CLOEXEC) ? FD_CLOEXEC : 0;
 	case F_SETFD:
 		return uk_fdtab_setflags(fd,
 			((int)arg & FD_CLOEXEC) ? O_CLOEXEC : 0);