Attachment 306503 Details for Bug 447518 – Proposed kernel (include/linux/capability.h) 'fix' for this issue

[patch] Proposed kernel (include/linux/capability.h) 'fix' for this issue

remain-source-compatible-with-32-bit-raw-legacy-capa.patch (text/plain), 5.68 KB, created by Andrew G. Morgan on 2008-05-23 14:28:17 UTC

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Creator: Andrew G. Morgan

Created: 2008-05-23 14:28:17 UTC

Size: 5.68 KB

patch

obsolete

>From ef100b0606f0e35f78be526b0840533ef188dbbe Mon Sep 17 00:00:00 2001
>From: Andrew G. Morgan <morgan@kernel.org>
>Date: Thu, 22 May 2008 22:57:54 -0700
>Subject: [PATCH] Remain source compatible with 32-bit raw legacy capability support.
>
>Source code out there hard-codes a notion of what the
>_LINUX_CAPABILITY_VERSION #define means in terms of the semantics of
>the raw capability system calls capget() and capset(). Its unfortunate,
>but true.
>
>As such, force this define to always retain its legacy value, and adopt
>a new #define strategy for the kernel's internal implementation of the
>preferred magic.
>
>[User space code continues to be encouraged to use the libcap API which
>protects the application from details like this.]
>
>Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
>Cc: Andrew Morton <akpm@linux-foundation.org>
>Cc: Chris Wright <chrisw@sous-sol.org>
>Cc: Serge E. Hallyn <serue@us.ibm.com>
>---
> fs/proc/array.c            |    2 +-
> include/linux/capability.h |   26 ++++++++++++++++++--------
> kernel/capability.c        |   12 ++++++------
> 3 files changed, 25 insertions(+), 15 deletions(-)
>
>diff --git a/fs/proc/array.c b/fs/proc/array.c
>index 9e3b8c3..797d775 100644
>--- a/fs/proc/array.c
>+++ b/fs/proc/array.c
>@@ -288,7 +288,7 @@ static void render_cap_t(struct seq_file *m, const char *header,
> 	seq_printf(m, "%s", header);
> 	CAP_FOR_EACH_U32(__capi) {
> 		seq_printf(m, "%08x",
>-			   a->cap[(_LINUX_CAPABILITY_U32S-1) - __capi]);
>+			   a->cap[(_KERNEL_CAPABILITY_U32S-1) - __capi]);
> 	}
> 	seq_printf(m, "\n");
> }
>diff --git a/include/linux/capability.h b/include/linux/capability.h
>index f4ea0dd..f88b4db 100644
>--- a/include/linux/capability.h
>+++ b/include/linux/capability.h
>@@ -34,9 +34,6 @@ struct task_struct;
> #define _LINUX_CAPABILITY_VERSION_2  0x20071026
> #define _LINUX_CAPABILITY_U32S_2     2
> 
>-#define _LINUX_CAPABILITY_VERSION    _LINUX_CAPABILITY_VERSION_2
>-#define _LINUX_CAPABILITY_U32S       _LINUX_CAPABILITY_U32S_2
>-
> typedef struct __user_cap_header_struct {
> 	__u32 version;
> 	int pid;
>@@ -77,10 +74,23 @@ struct vfs_cap_data {
> 	} data[VFS_CAP_U32];
> };
> 
>-#ifdef __KERNEL__
>+#ifndef __KERNEL__
>+
>+/*
>+ * Backwardly compatible definition for source code - trapped in a
>+ * 32-bit world. If you find you need this, please consider using
>+ * libcap to untrap yourself...
>+ */
>+#define _LINUX_CAPABILITY_VERSION  _LINUX_CAPABILITY_VERSION_1
>+#define _LINUX_CAPABILITY_U32S     _LINUX_CAPABILITY_U32S_1
>+
>+#else
>+
>+#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_2
>+#define _KERNEL_CAPABILITY_U32S    _LINUX_CAPABILITY_U32S_2
> 
> typedef struct kernel_cap_struct {
>-	__u32 cap[_LINUX_CAPABILITY_U32S];
>+	__u32 cap[_KERNEL_CAPABILITY_U32S];
> } kernel_cap_t;
> 
> #define _USER_CAP_HEADER_SIZE  (sizeof(struct __user_cap_header_struct))
>@@ -351,7 +361,7 @@ typedef struct kernel_cap_struct {
>  */
> 
> #define CAP_FOR_EACH_U32(__capi)  \
>-	for (__capi = 0; __capi < _LINUX_CAPABILITY_U32S; ++__capi)
>+	for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)
> 
> # define CAP_FS_MASK_B0     (CAP_TO_MASK(CAP_CHOWN)		\
> 			    | CAP_TO_MASK(CAP_DAC_OVERRIDE)	\
>@@ -361,7 +371,7 @@ typedef struct kernel_cap_struct {
> 
> # define CAP_FS_MASK_B1     (CAP_TO_MASK(CAP_MAC_OVERRIDE))
> 
>-#if _LINUX_CAPABILITY_U32S != 2
>+#if _KERNEL_CAPABILITY_U32S != 2
> # error Fix up hand-coded capability macro initializers
> #else /* HAND-CODED capability initializers */
> 
>@@ -372,7 +382,7 @@ typedef struct kernel_cap_struct {
> # define CAP_NFSD_SET     ((kernel_cap_t){{ CAP_FS_MASK_B0|CAP_TO_MASK(CAP_SYS_RESOURCE), \
> 					CAP_FS_MASK_B1 } })
> 
>-#endif /* _LINUX_CAPABILITY_U32S != 2 */
>+#endif /* _KERNEL_CAPABILITY_U32S != 2 */
> 
> #define CAP_INIT_INH_SET    CAP_EMPTY_SET
> 
>diff --git a/kernel/capability.c b/kernel/capability.c
>index 39e8193..8e5cc51 100644
>--- a/kernel/capability.c
>+++ b/kernel/capability.c
>@@ -88,7 +88,7 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
> 		tocopy = _LINUX_CAPABILITY_U32S_2;
> 		break;
> 	default:
>-		if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
>+		if (put_user(_KERNEL_CAPABILITY_VERSION, &header->version))
> 			return -EFAULT;
> 		return -EINVAL;
> 	}
>@@ -118,7 +118,7 @@ out:
> 	spin_unlock(&task_capability_lock);
> 
> 	if (!ret) {
>-		struct __user_cap_data_struct kdata[_LINUX_CAPABILITY_U32S];
>+		struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S];
> 		unsigned i;
> 
> 		for (i = 0; i < tocopy; i++) {
>@@ -128,7 +128,7 @@ out:
> 		}
> 
> 		/*
>-		 * Note, in the case, tocopy < _LINUX_CAPABILITY_U32S,
>+		 * Note, in the case, tocopy < _KERNEL_CAPABILITY_U32S,
> 		 * we silently drop the upper capabilities here. This
> 		 * has the effect of making older libcap
> 		 * implementations implicitly drop upper capability
>@@ -240,7 +240,7 @@ static inline int cap_set_all(kernel_cap_t *effective,
>  */
> asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
> {
>-	struct __user_cap_data_struct kdata[_LINUX_CAPABILITY_U32S];
>+	struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S];
> 	unsigned i, tocopy;
> 	kernel_cap_t inheritable, permitted, effective;
> 	__u32 version;
>@@ -260,7 +260,7 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
> 		tocopy = _LINUX_CAPABILITY_U32S_2;
> 		break;
> 	default:
>-		if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
>+		if (put_user(_KERNEL_CAPABILITY_VERSION, &header->version))
> 			return -EFAULT;
> 		return -EINVAL;
> 	}
>@@ -281,7 +281,7 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
> 		permitted.cap[i] = kdata[i].permitted;
> 		inheritable.cap[i] = kdata[i].inheritable;
> 	}
>-	while (i < _LINUX_CAPABILITY_U32S) {
>+	while (i < _KERNEL_CAPABILITY_U32S) {
> 		effective.cap[i] = 0;
> 		permitted.cap[i] = 0;
> 		inheritable.cap[i] = 0;
>-- 
>1.5.3.7
>

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Attachments on bug 447518: 306100 | 306104 | 306360 | 306503 | 306879