diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2024-06-21 21:54:50 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-12 11:11:29 +0200 |
| commit | 53f17409abf61f66b6f05aff795e938e5ba811d1 (patch) | |
| tree | f34e7153a4254c4f64e75a76b84bae4d593e0c1f /fs/binfmt_elf.c | |
| parent | 3c9e7909df159717486198b2046429318ab88b19 (diff) | |
ELF: fix kernel.randomize_va_space double read
[ Upstream commit 2a97388a807b6ab5538aa8f8537b2463c6988bd2 ]
ELF loader uses "randomize_va_space" twice. It is sysctl and can change
at any moment, so 2 loads could see 2 different values in theory with
unpredictable consequences.
Issue exactly one load for consistent value across one exec.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lore.kernel.org/r/3329905c-7eb8-400a-8f0a-d87cff979b5b@p183
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/binfmt_elf.c')
| -rw-r--r-- | fs/binfmt_elf.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 7b3d2d491407..fb2c8d14327a 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1008,7 +1008,8 @@ out_free_interp: if (elf_read_implies_exec(*elf_ex, executable_stack)) current->personality |= READ_IMPLIES_EXEC; - if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) + const int snapshot_randomize_va_space = READ_ONCE(randomize_va_space); + if (!(current->personality & ADDR_NO_RANDOMIZE) && snapshot_randomize_va_space) current->flags |= PF_RANDOMIZE; setup_new_exec(bprm); @@ -1300,7 +1301,7 @@ out_free_interp: mm->end_data = end_data; mm->start_stack = bprm->p; - if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { + if ((current->flags & PF_RANDOMIZE) && (snapshot_randomize_va_space > 1)) { /* * For architectures with ELF randomization, when executing * a loader directly (i.e. no interpreter listed in ELF |