Attachment 5242 Details for Bug 7067 – git-am format patch for 3.5.0.

[patch] git-am format patch for 3.5.0.

0001-Fix-bug-7067-Linux-asynchronous-IO-aio-can-cause-smb.patch (text/plain), 4.78 KB, created by Jeremy Allison on 2010-01-28 16:26:59 UTC

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Creator: Jeremy Allison

Created: 2010-01-28 16:26:59 UTC

Size: 4.78 KB

patch

obsolete

>From 1f01550360d719c617213db500206709adbbe0c5 Mon Sep 17 00:00:00 2001
>From: Jeremy Allison <jra@samba.org>
>Date: Tue, 26 Jan 2010 16:51:57 -0800
>Subject: [PATCH] Fix bug #7067 - Linux asynchronous IO (aio) can cause smbd to fail to respond to a read or write.
>
>Only works on Linux kernels 2.6.26 and above. Grants CAP_KILL capability
>to allow Linux threads under different euids to send signals to each other.
>
>Jeremy.
>(cherry picked from commit 899bd0005f56dcc1e95c3988d41ab3f628bb15db)
>---
> source3/include/smb.h |    3 +-
> source3/lib/system.c  |   65 ++++++++++++++++++++++++++++++++++++++++++++++---
> source3/smbd/server.c |    8 ++++++
> 3 files changed, 71 insertions(+), 5 deletions(-)
>
>diff --git a/source3/include/smb.h b/source3/include/smb.h
>index bc7a90d..041c96b 100644
>--- a/source3/include/smb.h
>+++ b/source3/include/smb.h
>@@ -1723,7 +1723,8 @@ minimum length == 24.
> enum smbd_capability {
>     KERNEL_OPLOCK_CAPABILITY,
>     DMAPI_ACCESS_CAPABILITY,
>-    LEASE_CAPABILITY
>+    LEASE_CAPABILITY,
>+    KILL_CAPABILITY
> };
> 
> /*
>diff --git a/source3/lib/system.c b/source3/lib/system.c
>index a58d903..9c1da3a 100644
>--- a/source3/lib/system.c
>+++ b/source3/lib/system.c
>@@ -883,6 +883,11 @@ char *sys_getwd(char *s)
> 
> #if defined(HAVE_POSIX_CAPABILITIES)
> 
>+/* This define hasn't made it into the glibc capabilities header yet. */
>+#ifndef SECURE_NO_SETUID_FIXUP
>+#define SECURE_NO_SETUID_FIXUP          2
>+#endif
>+
> /**************************************************************************
>  Try and abstract process capabilities (for systems that have them).
> ****************************************************************************/
>@@ -913,6 +918,32 @@ static bool set_process_capability(enum smbd_capability capability,
> 	}
> #endif
> 
>+#if defined(HAVE_PRCTL) && defined(PR_SET_SECUREBITS) && defined(SECURE_NO_SETUID_FIXUP)
>+        /* New way of setting capabilities as "sticky". */
>+
>+	/*
>+	 * Use PR_SET_SECUREBITS to prevent setresuid()
>+	 * atomically dropping effective capabilities on
>+	 * uid change. Only available in Linux kernels
>+	 * 2.6.26 and above.
>+	 *
>+	 * See here:
>+	 * http://www.kernel.org/doc/man-pages/online/pages/man7/capabilities.7.html
>+	 * for details.
>+	 *
>+	 * Specifically the CAP_KILL capability we need
>+	 * to allow Linux threads under different euids
>+	 * to send signals to each other.
>+	 */
>+
>+	if (prctl(PR_SET_SECUREBITS, 1 << SECURE_NO_SETUID_FIXUP)) {
>+		DEBUG(0,("set_process_capability: "
>+			"prctl PR_SET_SECUREBITS failed with error %s\n",
>+			strerror(errno) ));
>+		return false;
>+	}
>+#endif
>+
> 	cap = cap_get_proc();
> 	if (cap == NULL) {
> 		DEBUG(0,("set_process_capability: cap_get_proc failed: %s\n",
>@@ -941,6 +972,11 @@ static bool set_process_capability(enum smbd_capability capability,
> 			cap_vals[num_cap_vals++] = CAP_LEASE;
> #endif
> 			break;
>+		case KILL_CAPABILITY:
>+#ifdef CAP_KILL
>+			cap_vals[num_cap_vals++] = CAP_KILL;
>+#endif
>+			break;
> 	}
> 
> 	SMB_ASSERT(num_cap_vals <= ARRAY_SIZE(cap_vals));
>@@ -950,16 +986,37 @@ static bool set_process_capability(enum smbd_capability capability,
> 		return True;
> 	}
> 
>-	cap_set_flag(cap, CAP_EFFECTIVE, num_cap_vals, cap_vals,
>-		enable ? CAP_SET : CAP_CLEAR);
>+	/*
>+	 * Ensure the capability is effective. We assume that as a root
>+	 * process it's always permitted.
>+	 */
>+
>+	if (cap_set_flag(cap, CAP_EFFECTIVE, num_cap_vals, cap_vals,
>+			enable ? CAP_SET : CAP_CLEAR) == -1) {
>+		DEBUG(0, ("set_process_capability: cap_set_flag effective "
>+			"failed (%d): %s\n",
>+			(int)capability,
>+			strerror(errno)));
>+		cap_free(cap);
>+		return false;
>+	}
> 
> 	/* We never want to pass capabilities down to our children, so make
> 	 * sure they are not inherited.
> 	 */
>-	cap_set_flag(cap, CAP_INHERITABLE, num_cap_vals, cap_vals, CAP_CLEAR);
>+	if (cap_set_flag(cap, CAP_INHERITABLE, num_cap_vals,
>+			cap_vals, CAP_CLEAR) == -1) {
>+		DEBUG(0, ("set_process_capability: cap_set_flag inheritable "
>+			"failed (%d): %s\n",
>+			(int)capability,
>+			strerror(errno)));
>+		cap_free(cap);
>+		return false;
>+	}
> 
> 	if (cap_set_proc(cap) == -1) {
>-		DEBUG(0, ("set_process_capability: cap_set_proc failed: %s\n",
>+		DEBUG(0, ("set_process_capability: cap_set_flag (%d) failed: %s\n",
>+			(int)capability,
> 			strerror(errno)));
> 		cap_free(cap);
> 		return False;
>diff --git a/source3/smbd/server.c b/source3/smbd/server.c
>index 09ad8d8..fb0efd2 100644
>--- a/source3/smbd/server.c
>+++ b/source3/smbd/server.c
>@@ -1047,6 +1047,14 @@ extern void build_options(bool screen);
> 	gain_root_privilege();
> 	gain_root_group_privilege();
> 
>+	/*
>+	 * Ensure we have CAP_KILL capability set on Linux,
>+	 * where we need this to communicate with threads.
>+	 * This is inherited by new threads, but not by new
>+	 * processes across exec().
>+	 */
>+	set_effective_capability(KILL_CAPABILITY);
>+
> 	fault_setup((void (*)(void *))exit_server_fault);
> 	dump_core_setup("smbd");
> 
>-- 
>1.6.6
>

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Attachments on bug 7067: 5242 | 5243 | 5244