On Fri, 2020-10-16 at 01:38 +0200, Andreas Rheinhardt wrote: > CAUTION: This email originated from outside of the organization. Do not click > links or open attachments unless you recognize the sender and know the > content is safe. > > > Joakim Tjernlund: > > From > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugs.chromium.org%2Fp%2Fchromium%2Fissues%2Fdetail%3Fid%3D1095962&data=02%7C01%7Cjoakim.tjernlund%40infinera.com%7Cb1993f8740d849953d7908d871638074%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C0%7C637384019459705602&sdata=Lcc%2BcVTlLU1y6EqrMXwfXJ0enHYlIRTBJyGkQgQEviA%3D&reserved=0 > > ---------------------------- > > This seems to be caused by the custom handling of "av_max_alloc(0)" in > > Chromium's ffmpeg fork to mean unlimited (added in [1]). > > > > Upstream ffmpeg doesn't treat 0 as a special value; versions before 4.3 > > seemingly worked > > because 32 was subtracted from max_alloc_size (set to 0 by Chromium) > > resulting in an > > integer underflow, making the effective limit be SIZE_MAX - 31. > > > > Now that the above underflow doesn't happen, the tab just crashes. The > > upstream change > > for no longer subtracting 32 from max_alloc_size was included in ffmpeg > > 4.3. [2] > > > > [1] > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fchromium-review.googlesource.com%2Fc%2Fchromium%2Fthird_party%2Fffmpeg%2F%2B%2F73563&data=02%7C01%7Cjoakim.tjernlund%40infinera.com%7Cb1993f8740d849953d7908d871638074%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C0%7C637384019459705602&sdata=4%2BwE%2FMIcFSZlTdgzbVdbEBdYlO6Cdx%2Fh%2BLfjtrxCGec%3D&reserved=0 > > [2] > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2FFFmpeg%2FFFmpeg%2Fcommit%2F731c77589841&data=02%7C01%7Cjoakim.tjernlund%40infinera.com%7Cb1993f8740d849953d7908d871638074%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C0%7C637384019459705602&sdata=fuSKAPgqOiDsqwjl1m6P5IPF4a1K%2ByUK1c9e518aV6c%3D&reserved=0 > > --------------------------- > > > > Restore av_malloc_max(0) to MAX_INT fixing MS Teams, Discord older chromium > > etc. > > > > Signed-off-by: Joakim Tjernlund <joakim.tjernl...@infinera.com> > > --- > > > > v2: Cover the full API range 0-31 > > > > v3: Closer compat with < 4.3 ffmpeg > > > > libavutil/mem.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/libavutil/mem.c b/libavutil/mem.c > > index cfb6d8a..bd1fb85 100644 > > --- a/libavutil/mem.c > > +++ b/libavutil/mem.c > > @@ -71,6 +71,8 @@ void free(void *ptr); > > static size_t max_alloc_size= INT_MAX; > > > > void av_max_alloc(size_t max){ > > + if (max < 32) > > + max = SIZE_MAX - max; /* be compatible to older(< 4.3) versions */ > > max_alloc_size = max; > > } > > > > > For full compatibility it should be SIZE_MAX - 32 + max. > OK, v4 sent.
> But why don't you go the way of fixing the broken apps? Because they are binary apps, in my case from Microsoft. Their MS Teams is based on a Chromium/Electron framework that(I hope) will be updated at some point. > > - Andreas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
