diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2011-11-02 13:37:41 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-11-11 09:36:29 -0800 |
| commit | bfcf6092c5b8789a179e40992ca041bbdbb859cc (patch) | |
| tree | 5977df15ac62ab5073893a1e7d5d655f4ad1ddca /fs | |
| parent | 68fe9d9c796303de600dbc622086768ca4d8408b (diff) | |
| download | lwn-bfcf6092c5b8789a179e40992ca041bbdbb859cc.tar.gz lwn-bfcf6092c5b8789a179e40992ca041bbdbb859cc.zip | |
binfmt_elf: fix PIE execution with randomization disabled
commit a3defbe5c337dbc6da911f8cc49ae3cc3b49b453 upstream.
The case of address space randomization being disabled in runtime through
randomize_va_space sysctl is not treated properly in load_elf_binary(),
resulting in SIGKILL coming at exec() time for certain PIE-linked binaries
in case the randomization has been disabled at runtime prior to calling
exec().
Handle the randomize_va_space == 0 case the same way as if we were not
supporting .text randomization at all.
Based on original patch by H.J. Lu and Josh Boyer.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: H.J. Lu <hongjiu.lu@intel.com>
Cc: <stable@kernel.org>
Tested-by: Josh Boyer <jwboyer@redhat.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/binfmt_elf.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 303983fabfd6..9ba2ac755a7e 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -796,7 +796,16 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) * might try to exec. This is because the brk will * follow the loader, and is not movable. */ #if defined(CONFIG_X86) || defined(CONFIG_ARM) - load_bias = 0; + /* Memory randomization might have been switched off + * in runtime via sysctl. + * If that is the case, retain the original non-zero + * load_bias value in order to establish proper + * non-randomized mappings. + */ + if (current->flags & PF_RANDOMIZE) + load_bias = 0; + else + load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); #else load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); #endif |