From: Andrey Erokhin Date: Sat, 22 Nov 2025 20:19:09 +0000 (+0500) Subject: 9pfs: local: read native symlinks when security-model=mapped X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=22296f2db9f17f9954f85de9e99b09498936eb51;p=thirdparty%2Fqemu.git 9pfs: local: read native symlinks when security-model=mapped Directories attached using virtfs with security-model=mapped may contain native symlinks This can happen e.g. when booting from a rootfs directory tree (usually with a writable overlay set up on the host side) Currently, when security-model=mapped[-xattr|-file], QEMU assumes that host-side "symlinks" are in the mapped format, i.e. are regular files storing the linked path, so it tries to open with O_NOFOLLOW and fails with ELOOP on native symlinks This patch introduces a fallback for such cases: reuse security-model=[none|passthrough] else if branch logic where readlink will be called for the path basename Resolves: https://gitlab.com/qemu-project/qemu/-/issues/173 Signed-off-by: Andrey Erokhin Reviewed-by: Greg Kurz Link: https://lore.kernel.org/qemu-devel/3c35955d-a57e-4203-81c5-395146e23f83@gmail.com Signed-off-by: Christian Schoenebeck --- diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index c3745f2839..24cb1da90a 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -469,12 +469,16 @@ static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path, fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0); if (fd == -1) { + if (errno == ELOOP) { + goto native_symlink; + } return -1; } tsize = RETRY_ON_EINTR(read(fd, (void *)buf, bufsz)); close_preserve_errno(fd); } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || (fs_ctx->export_flags & V9FS_SM_NONE)) { + native_symlink:; char *dirpath = g_path_get_dirname(fs_path->data); char *name = g_path_get_basename(fs_path->data); int dirfd;