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| author | Alessandro Astone <ales.astone@gmail.com> | 2022-11-30 03:58:04 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-02 17:40:04 +0100 |
| commit | 017de842533f4334d646f1d480f591f4ca9f5c7a (patch) | |
| tree | 09a18abf8c468af7f959e9aacf9f113740f340bc | |
| parent | 2e3c27f24173c6f3d799080da82126fa044a2f5e (diff) | |
| download | linux-017de842533f4334d646f1d480f591f4ca9f5c7a.tar.gz linux-017de842533f4334d646f1d480f591f4ca9f5c7a.tar.bz2 linux-017de842533f4334d646f1d480f591f4ca9f5c7a.zip | |
binder: Address corner cases in deferred copy and fixup
commit 2d1746e3fda0c3612143d7c06f8e1d1830c13e23 upstream.
When handling BINDER_TYPE_FDA object we are pushing a parent fixup
with a certain skip_size but no scatter-gather copy object, since
the copy is handled standalone.
If BINDER_TYPE_FDA is the last children the scatter-gather copy
loop will never stop to skip it, thus we are left with an item in
the parent fixup list. This will trigger the BUG_ON().
This is reproducible in android when playing a video.
We receive a transaction that looks like this:
obj[0] BINDER_TYPE_PTR, parent
obj[1] BINDER_TYPE_PTR, child
obj[2] BINDER_TYPE_PTR, child
obj[3] BINDER_TYPE_FDA, child
Fixes: 09184ae9b575 ("binder: defer copies of pre-patched txn data")
Acked-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Alessandro Astone <ales.astone@gmail.com>
Link: https://lore.kernel.org/r/20220415120015.52684-2-ales.astone@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/android/binder.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 398ce65b578b..1ba8a98094b4 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2695,6 +2695,7 @@ static int binder_do_deferred_txn_copies(struct binder_alloc *alloc, { int ret = 0; struct binder_sg_copy *sgc, *tmpsgc; + struct binder_ptr_fixup *tmppf; struct binder_ptr_fixup *pf = list_first_entry_or_null(pf_head, struct binder_ptr_fixup, node); @@ -2749,7 +2750,11 @@ static int binder_do_deferred_txn_copies(struct binder_alloc *alloc, list_del(&sgc->node); kfree(sgc); } - BUG_ON(!list_empty(pf_head)); + list_for_each_entry_safe(pf, tmppf, pf_head, node) { + BUG_ON(pf->skip_size == 0); + list_del(&pf->node); + kfree(pf); + } BUG_ON(!list_empty(sgc_head)); return ret > 0 ? -EINVAL : ret; |