Ulrich Drepper
f23513e8d9
Introduce O_CLOEXEC ...
The problem is as follows: in multi-threaded code (or more correctly: all
code using clone() with CLONE_FILES) we have a race when exec'ing.
thread #1 thread #2
fd=open()
fork + exec
fcntl(fd,F_SETFD,FD_CLOEXEC)
In some applications this can happen frequently. Take a web browser. One
thread opens a file and another thread starts, say, an external PDF viewer.
The result can even be a security issue if that open file descriptor
refers to a sensitive file and the external program can somehow be tricked
into using that descriptor.
Just adding O_CLOEXEC support to open() doesn't solve the whole set of
problems. There are other ways to create file descriptors (socket,
epoll_create, Unix domain socket transfer, etc). These can and should be
addressed separately though. open() is such an easy case that it makes not
much sense putting the fix off.
The test program:
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif
int
main (int argc, char *argv[])
{
int fd;
if (argc > 1)
{
fd = atol (argv[1]);
printf ("child: fd = %d\n", fd);
if (fcntl (fd, F_GETFD) == 0 || errno != EBADF)
{
puts ("file descriptor valid in child");
return 1;
}
return 0;
}
fd = open ("/proc/self/exe", O_RDONLY | O_CLOEXEC);
printf ("in parent: new fd = %d\n", fd);
char buf[20];
snprintf (buf, sizeof (buf), "%d", fd);
execl ("/proc/self/exe", argv[0], buf, NULL);
puts ("execl failed");
return 1;
}
[kyle@parisc-linux.org: parisc fix]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:45 -07:00
[PARISC] Add support for Quicksilver AGPGART
2006-10-04 06:50:16 -06:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
atomic.h: atomic_add_unless as inline. Remove system.h atomic.h circular dependency
2007-05-08 11:15:20 -07:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] add ASM_EXCEPTIONTABLE_ENTRY() macro
2007-02-17 01:16:26 -05:00
[PARISC] Clean up the cache and tlb headers
2007-02-17 00:41:30 -05:00
[PARISC] Add prototypes for flush_user_dcache_range and flush_user_icache_range
2007-02-17 00:43:51 -05:00
[NET]: PARISC checksum annotations and cleanups.
2006-12-02 21:23:10 -08:00
wrap access to thread_info
2007-05-09 12:30:56 -07:00
[PARISC] Arch-specific compat signals
2006-01-22 20:57:42 -05:00
Driver core: add dev_archdata to struct device
2006-12-01 14:52:01 -08:00
[PARISC] Fix ccio_request_resource when CONFIG_IOMMU_CCIO is not defined
2006-12-08 00:33:59 -05:00
Fix misc .c/.h comment typos
2006-11-30 05:24:39 +01:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
Introduce O_CLOEXEC
2007-07-16 09:05:45 -07:00
[PATCH] irq-flags: PARISC: Use the new IRQF_ constants
2006-07-02 13:58:47 -07:00
[PATCH] mm: pagefault_{disable,enable}()
2006-12-07 08:39:21 -08:00
[PARISC] Use kzalloc and other janitor-style cleanups
2006-01-22 20:26:31 -05:00
[PARISC] fix section mismatches in arch/parisc/kernel
2007-05-27 13:36:27 -04:00
[PATCH] genirq: add ->retrigger() irq op to consolidate hw_irq_resend()
2006-06-29 10:26:23 -07:00
Merge master.kernel.org:/pub/scm/linux/kernel/git/kyle/parisc-2.6
2007-02-26 12:48:06 -08:00
[PARISC] Allow nested interrupts
2006-10-04 06:48:57 -06:00
Build fixes for struct pt_regs removal
2006-10-06 20:47:23 -06:00
Add empty Kbuild files for 'make headers_install' in remaining arches.
2006-06-18 12:58:53 +01:00
move die notifier handling to common code
2007-05-08 11:15:04 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PARISC] Convert soft power switch driver to kthread
2007-02-17 01:03:43 -05:00
[PARISC] fix trivial spelling nit in asm/linkage.h
2007-05-30 02:14:36 -04:00
local_t: parisc cleanup
2007-05-08 11:15:20 -07:00
[PARISC] Add asm-parisc/mckinley.h bus header
2006-10-04 06:45:48 -06:00
[PATCH] Remove final references to deprecated "MAP_ANON" page protection flag
2007-02-11 10:51:17 -08:00
Detach sched.h from mm.h
2007-05-21 09:18:19 -07:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] Use CONFIG_HZ to determine interval timer rate (aka clock ticks)
2006-10-04 06:47:46 -06:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
PCI: remove pci_dac_dma_... APIs
2007-07-11 16:02:11 -07:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] Clarify pdc_stable license terms
2006-03-30 17:48:41 +00:00
[PARISC] Remove duplicate PDC_PAT_CELL defines
2006-12-08 00:34:47 -05:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
page table handling cleanup
2007-07-16 09:05:36 -07:00
Consolidate asm/poll.h
2007-05-11 08:29:34 -07:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] PA7200 also supports prefetch for read
2006-10-04 06:44:58 -06:00
[PARISC] fix section mismatches in arch/parisc/kernel
2007-05-27 13:36:27 -04:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Fix misc .c/.h comment typos
2006-11-30 05:24:39 +01:00
[PARISC] Arch-specific compat signals
2006-01-22 20:57:42 -05:00
fix file specification in comments
2006-10-03 23:01:26 +02:00
PCI: scatterlist.h needs types.h
2007-05-02 19:02:34 -07:00
[PATCH] Fix incorrent type of flags in <asm/semaphore.h>
2006-11-26 16:30:29 -08:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] Clean up asm-parisc/serial.h
2006-10-04 06:47:03 -06:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] kill ENTRY_SYS_CPUS
2007-02-17 01:11:41 -05:00
[NET]: Adding SO_TIMESTAMPNS / SCM_TIMESTAMPNS support
2007-04-25 22:24:21 -07:00
[NET]: Introduce SIOCGSTAMPNS ioctl to get timestamps with nanosec resolution
2007-04-25 22:24:04 -07:00
[PARISC] Enable interrupts while spinning
2006-10-04 06:48:17 -06:00
[PARISC] "Fix" circular includes
2007-02-17 00:43:10 -05:00
[PATCH] use __u64 rather than u64 in parisc statfs structs
2007-02-08 18:56:57 -05:00
[PARISC] Fix unwinder on 64-bit kernels
2007-06-21 17:46:21 -04:00
lots-of-architectures: enable arbitary speed tty support
2007-07-10 17:51:13 -07:00
[PATCH] consolidate line discipline number definitions
2007-02-11 10:51:26 -08:00
[PARISC] Add TIF_RESTORE_SIGMASK support
2007-02-17 01:06:04 -05:00
Detach sched.h from mm.h
2007-05-21 09:18:19 -07:00
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
2007-02-17 01:17:13 -05:00
[PARISC] add ASM_EXCEPTIONTABLE_ENTRY() macro
2007-02-17 01:16:26 -05:00
[PARISC] Wire up utimensat/signalfd/timerfd/eventfd syscalls
2007-05-27 15:19:58 -04:00
f23513e8d9