DEBIAN-CVE-2024-56653

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btmtk: avoid UAF in btmtkprocesscoredump hcidevcdappend may lead to the release of the skb, so it cannot be accessed once it is called. ================================================================== BUG: KASAN: slab-use-after-free in btmtkprocesscoredump+0x2a7/0x2d0 [btmtk] Read of size 4 at addr ffff888033cfabb0 by task kworker/0:3/82 CPU: 0 PID: 82 Comm: kworker/0:3 Tainted: G U 6.6.40-lockdep-03464-g1d8b4eb3060e #1 b0b3c1cc0c842735643fb411799d97921d1f688c Hardware name: Google YaviksUfs/YaviksUfs, BIOS GoogleYaviksUfs.15217.552.0 05/07/2024 Workqueue: events btusbrxwork [btusb] Call Trace: <TASK> dumpstacklvl+0xfd/0x150 printreport+0x131/0x780 kasanreport+0x177/0x1c0 btmtkprocesscoredump+0x2a7/0x2d0 [btmtk 03edd567dd71a65958807c95a65db31d433e1d01] btusbrecvaclmtk+0x11c/0x1a0 [btusb 675430d1e87c4f24d0c1f80efe600757a0f32bec] btusbrxwork+0x9e/0xe0 [btusb 675430d1e87c4f24d0c1f80efe600757a0f32bec] workerthread+0xe44/0x2cc0 kthread+0x2ff/0x3a0 retfromfork+0x51/0x80 retfromforkasm+0x1b/0x30 </TASK> Allocated by task 82: stacktracesave+0xdc/0x190 kasansettrack+0x4e/0x80 kasanslaballoc+0x4e/0x60 kmemcachealloc+0x19f/0x360 skbclone+0x132/0xf70 btusbrecvaclmtk+0x104/0x1a0 [btusb] btusbrxwork+0x9e/0xe0 [btusb] workerthread+0xe44/0x2cc0 kthread+0x2ff/0x3a0 retfromfork+0x51/0x80 retfromforkasm+0x1b/0x30 Freed by task 1733: stacktracesave+0xdc/0x190 kasansettrack+0x4e/0x80 kasansavefreeinfo+0x28/0xb0 kasanslabfree+0xfd/0x170 kmemcachefree+0x183/0x3f0 hcidevcdrx+0x91a/0x2060 [bluetooth] workerthread+0xe44/0x2cc0 kthread+0x2ff/0x3a0 retfromfork+0x51/0x80 retfromforkasm+0x1b/0x30 The buggy address belongs to the object at ffff888033cfab40 which belongs to the cache skbuffheadcache of size 232 The buggy address is located 112 bytes inside of freed 232-byte region [ffff888033cfab40, ffff888033cfac28) The buggy address belongs to the physical page: page:00000000a174ba93 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33cfa head:00000000a174ba93 order:1 entiremapcount:0 nrpagesmapped:0 pincount:0 anon flags: 0x4000000000000840(slab|head|zone=1) pagetype: 0xffffffff() raw: 4000000000000840 ffff888100848a00 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080190019 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888033cfaa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888033cfab00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888033cfab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888033cfac00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff888033cfac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Check if we need to call hcidevcdcomplete before calling hcidevcdappend. That requires that we check data->cdinfo.cnt >= MTKCOREDUMPNUM instead of data->cdinfo.cnt > MTKCOREDUMPNUM, as we increment data->cdinfo.cnt only once the call to hcidevcd_append succeeds.