add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/mm/shmem.c
..
..
@@ -3424,6 +3424,8 @@
3424
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 	unsigned long long size;
3425
3425
 	char *rest;
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 	int opt;
3427
+	kuid_t kuid;
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+	kgid_t kgid;
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3429
 
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 	opt = fs_parse(fc, shmem_fs_parameters, param, &result);
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 	if (opt < 0)
..
..
@@ -3459,14 +3461,32 @@
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 		ctx->mode = result.uint_32 & 07777;
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 		break;
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 	case Opt_uid:
3462
-		ctx->uid = make_kuid(current_user_ns(), result.uint_32);
3463
-		if (!uid_valid(ctx->uid))
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+		kuid = make_kuid(current_user_ns(), result.uint_32);
3465
+		if (!uid_valid(kuid))
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 			goto bad_value;
3467
+
3468
+		/*
3469
+		 * The requested uid must be representable in the
3470
+		 * filesystem's idmapping.
3471
+		 */
3472
+		if (!kuid_has_mapping(fc->user_ns, kuid))
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+			goto bad_value;
3474
+
3475
+		ctx->uid = kuid;
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 		break;
3466
3477
 	case Opt_gid:
3467
-		ctx->gid = make_kgid(current_user_ns(), result.uint_32);
3468
-		if (!gid_valid(ctx->gid))
3478
+		kgid = make_kgid(current_user_ns(), result.uint_32);
3479
+		if (!gid_valid(kgid))
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 			goto bad_value;
3481
+
3482
+		/*
3483
+		 * The requested gid must be representable in the
3484
+		 * filesystem's idmapping.
3485
+		 */
3486
+		if (!kgid_has_mapping(fc->user_ns, kgid))
3487
+			goto bad_value;
3488
+
3489
+		ctx->gid = kgid;
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3490
 		break;
3471
3491
 	case Opt_huge:
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 		ctx->huge = result.uint_32;
..
..
@@ -4100,7 +4120,7 @@
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 	.name		= "tmpfs",
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 	.init_fs_context = ramfs_init_fs_context,
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 	.parameters	= ramfs_fs_parameters,
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-	.kill_sb	= kill_litter_super,
4123
+	.kill_sb	= ramfs_kill_sb,
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 	.fs_flags	= FS_USERNS_MOUNT,
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 };
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