{"id":"DEBIAN-CVE-2022-49287","details":"In the Linux kernel, the following vulnerability has been resolved:  tpm: fix reference counting for struct tpm_chip  The following sequence of operations results in a refcount warning:  1. Open device /dev/tpmrm. 2. Remove module tpm_tis_spi. 3. Write a TPM command to the file descriptor opened at step 1.  ------------[ cut here ]------------ WARNING: CPU: 3 PID: 1161 at lib/refcount.c:25 kobject_get+0xa0/0xa4 refcount_t: addition on 0; use-after-free. Modules linked in: tpm_tis_spi tpm_tis_core tpm mdio_bcm_unimac brcmfmac sha256_generic libsha256 sha256_arm hci_uart btbcm bluetooth cfg80211 vc4 brcmutil ecdh_generic ecc snd_soc_core crc32_arm_ce libaes raspberrypi_hwmon ac97_bus snd_pcm_dmaengine bcm2711_thermal snd_pcm snd_timer genet snd phy_generic soundcore [last unloaded: spi_bcm2835] CPU: 3 PID: 1161 Comm: hold_open Not tainted 5.10.0ls-main-dirty #2 Hardware name: BCM2711 [\u003cc0410c3c\u003e] (unwind_backtrace) from [\u003cc040b580\u003e] (show_stack+0x10/0x14) [\u003cc040b580\u003e] (show_stack) from [\u003cc1092174\u003e] (dump_stack+0xc4/0xd8) [\u003cc1092174\u003e] (dump_stack) from [\u003cc0445a30\u003e] (__warn+0x104/0x108) [\u003cc0445a30\u003e] (__warn) from [\u003cc0445aa8\u003e] (warn_slowpath_fmt+0x74/0xb8) [\u003cc0445aa8\u003e] (warn_slowpath_fmt) from [\u003cc08435d0\u003e] (kobject_get+0xa0/0xa4) [\u003cc08435d0\u003e] (kobject_get) from [\u003cbf0a715c\u003e] (tpm_try_get_ops+0x14/0x54 [tpm]) [\u003cbf0a715c\u003e] (tpm_try_get_ops [tpm]) from [\u003cbf0a7d6c\u003e] (tpm_common_write+0x38/0x60 [tpm]) [\u003cbf0a7d6c\u003e] (tpm_common_write [tpm]) from [\u003cc05a7ac0\u003e] (vfs_write+0xc4/0x3c0) [\u003cc05a7ac0\u003e] (vfs_write) from [\u003cc05a7ee4\u003e] (ksys_write+0x58/0xcc) [\u003cc05a7ee4\u003e] (ksys_write) from [\u003cc04001a0\u003e] (ret_fast_syscall+0x0/0x4c) Exception stack(0xc226bfa8 to 0xc226bff0) bfa0:                   00000000 000105b4 00000003 beafe664 00000014 00000000 bfc0: 00000000 000105b4 000103f8 00000004 00000000 00000000 b6f9c000 beafe684 bfe0: 0000006c beafe648 0001056c b6eb6944 ---[ end trace d4b8409def9b8b1f ]---  The reason for this warning is the attempt to get the chip-\u003edev reference in tpm_common_write() although the reference counter is already zero.  Since commit 8979b02aaf1d (\"tpm: Fix reference count to main device\") the extra reference used to prevent a premature zero counter is never taken, because the required TPM_CHIP_FLAG_TPM2 flag is never set.  Fix this by moving the TPM 2 character device handling from tpm_chip_alloc() to tpm_add_char_device() which is called at a later point in time when the flag has been set in case of TPM2.  Commit fdc915f7f719 (\"tpm: expose spaces via a device link /dev/tpmrm\u003cn\u003e\") already introduced function tpm_devs_release() to release the extra reference but did not implement the required put on chip-\u003edevs that results in the call of this function.  Fix this by putting chip-\u003edevs in tpm_chip_unregister().  Finally move the new implementation for the TPM 2 handling into a new function to avoid multiple checks for the TPM_CHIP_FLAG_TPM2 flag in the good case and error cases.","modified":"2026-09-01T16:05:30.701498611Z","published":"2025-02-26T07:01:05.557Z","upstream":["CVE-2022-49287"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-49287"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49287.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49287.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49287.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}