# CVE-2022-48838: linux: In the Linux kernel, the following vulnerability has been resolved: usb: gadget: Fix use-after-free bug by not setti... CVE-2022-48838 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-48838, released July 16, 2024. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2022-48838 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0024 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 16, 2024 ## Description In the Linux kernel, the following vulnerability has been resolved: usb: gadget: Fix use-after-free bug by not setting udc->dev.driver The syzbot fuzzer found a use-after-free bug: BUG: KASAN: use-after-free in dev_uevent+0x712/0x780 drivers/base/core.c:2320 Read of size 8 at addr ffff88802b934098 by task udevd/3689 CPU: 2 PID: 3689 Comm: udevd Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 dev_uevent+0x712/0x780 drivers/base/core.c:2320 uevent_show+0x1b8/0x380 drivers/base/core.c:2391 dev_attr_show+0x4b/0x90 drivers/base/core.c:2094 Although the bug manifested in the driver core, the real cause was a race with the gadget core. dev_uevent() does: if (dev->driver) add_uevent_var(env, "DRIVER=%s", dev->driver->name); and between the test and the dereference of dev->driver, the gadget core sets dev->driver to NULL. The race wouldn't occur if the gadget core registered its devices on a real bus, using the standard synchronization techniques of the driver core. However, it's not necessary to make such a large change in order to fix this bug; all we need to do is make sure that udc->dev.driver is always NULL. In fact, there is no reason for udc->dev.driver ever to be set to anything, let alone to the value it currently gets: the address of the gadget's driver. After all, a gadget driver only knows how to manage a gadget, not how to manage a UDC. This patch simply removes the statements in the gadget core that touch udc->dev.driver. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | linux Debian 12.15 (bookworm) | 5.17.3-1 | [DEBIAN-CVE-2022-48838](https://patchblox.com/security/data/fix/linux/debian-cve-2022-48838.md) | Jul 16, 2024 | | Linux | linux Debian 13.5 (trixie) | 5.17.3-1 | [DEBIAN-CVE-2022-48838](https://patchblox.com/security/data/fix/linux/debian-cve-2022-48838.md) | Jul 16, 2024 | | Linux | linux Debian 14 | 5.17.3-1 | [DEBIAN-CVE-2022-48838](https://patchblox.com/security/data/fix/linux/debian-cve-2022-48838.md) | Jul 16, 2024 | --- Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.