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| author | Todd Kjos <tkjos@android.com> | 2019-04-24 12:31:18 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-25 21:26:49 +0200 |
| commit | 0b0509508beff65c1d50541861bc0d4973487dc5 (patch) | |
| tree | 6237e6db6fc0f1355c60e9c9f6c924178219db59 | |
| parent | d2f4a83fe3f7fcc2a8a10a39e367c5d1c6670327 (diff) | |
| download | linux-stable-0b0509508beff65c1d50541861bc0d4973487dc5.tar.gz linux-stable-0b0509508beff65c1d50541861bc0d4973487dc5.tar.bz2 linux-stable-0b0509508beff65c1d50541861bc0d4973487dc5.zip | |
binder: check for overflow when alloc for security context
When allocating space in the target buffer for the security context,
make sure the extra_buffers_size doesn't overflow. This can only
happen if the given size is invalid, but an overflow can turn it
into a valid size. Fail the transaction if an overflow is detected.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/android/binder.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 4b9c7ca492e6..6f0712f0767c 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3121,6 +3121,7 @@ static void binder_transaction(struct binder_proc *proc, if (target_node && target_node->txn_security_ctx) { u32 secid; + size_t added_size; security_task_getsecid(proc->tsk, &secid); ret = security_secid_to_secctx(secid, &secctx, &secctx_sz); @@ -3130,7 +3131,15 @@ static void binder_transaction(struct binder_proc *proc, return_error_line = __LINE__; goto err_get_secctx_failed; } - extra_buffers_size += ALIGN(secctx_sz, sizeof(u64)); + added_size = ALIGN(secctx_sz, sizeof(u64)); + extra_buffers_size += added_size; + if (extra_buffers_size < added_size) { + /* integer overflow of extra_buffers_size */ + return_error = BR_FAILED_REPLY; + return_error_param = EINVAL; + return_error_line = __LINE__; + goto err_bad_extra_size; + } } trace_binder_transaction(reply, t, target_node); @@ -3480,6 +3489,7 @@ err_copy_data_failed: t->buffer->transaction = NULL; binder_alloc_free_buf(&target_proc->alloc, t->buffer); err_binder_alloc_buf_failed: +err_bad_extra_size: if (secctx) security_release_secctx(secctx, secctx_sz); err_get_secctx_failed: |