From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Qiushi Wu <wu000273@umn.edu>,
Kees Cook <keescook@chromium.org>,
Johan Hovold <johan@kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: [PATCH 5.10 14/23] firmware: qemu_fw_cfg: fix NULL-pointer deref on duplicate entries
Date: Tue, 18 Jan 2022 17:05:54 +0100 [thread overview]
Message-ID: <20220118160451.723590076@linuxfoundation.org> (raw)
In-Reply-To: <20220118160451.233828401@linuxfoundation.org>
From: Johan Hovold <johan@kernel.org>
commit d3e305592d69e21e36b76d24ca3c01971a2d09be upstream.
Commit fe3c60684377 ("firmware: Fix a reference count leak.") "fixed"
a kobject leak in the file registration helper by properly calling
kobject_put() for the entry in case registration of the object fails
(e.g. due to a name collision).
This would however result in a NULL pointer dereference when the
release function tries to remove the never added entry from the
fw_cfg_entry_cache list.
Fix this by moving the list-removal out of the release function.
Note that the offending commit was one of the benign looking umn.edu
fixes which was reviewed but not reverted. [1][2]
[1] https://lore.kernel.org/r/202105051005.49BFABCE@keescook
[2] https://lore.kernel.org/all/YIg7ZOZvS3a8LjSv@kroah.com
Fixes: fe3c60684377 ("firmware: Fix a reference count leak.")
Cc: stable@vger.kernel.org # 5.8
Cc: Qiushi Wu <wu000273@umn.edu>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211201132528.30025-2-johan@kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/firmware/qemu_fw_cfg.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -388,9 +388,7 @@ static void fw_cfg_sysfs_cache_cleanup(v
struct fw_cfg_sysfs_entry *entry, *next;
list_for_each_entry_safe(entry, next, &fw_cfg_entry_cache, list) {
- /* will end up invoking fw_cfg_sysfs_cache_delist()
- * via each object's release() method (i.e. destructor)
- */
+ fw_cfg_sysfs_cache_delist(entry);
kobject_put(&entry->kobj);
}
}
@@ -448,7 +446,6 @@ static void fw_cfg_sysfs_release_entry(s
{
struct fw_cfg_sysfs_entry *entry = to_entry(kobj);
- fw_cfg_sysfs_cache_delist(entry);
kfree(entry);
}
next prev parent reply other threads:[~2022-01-18 16:09 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-18 16:05 [PATCH 5.10 00/23] 5.10.93-rc1 review Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 01/23] kbuild: Add $(KBUILD_HOSTLDFLAGS) to has_libelf test Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 02/23] devtmpfs regression fix: reconfigure on each mount Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 03/23] orangefs: Fix the size of a memory allocation in orangefs_bufmap_alloc() Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 04/23] remoteproc: qcom: pil_info: Dont memcpy_toio more than is provided Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 05/23] vfs: fs_context: fix up param length parsing in legacy_parse_param Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 06/23] perf: Protect perf_guest_cbs with RCU Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 07/23] KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 08/23] KVM: s390: Clarify SIGP orders versus STOP/RESTART Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 09/23] 9p: only copy valid iattrs in 9P2000.L setattr implementation Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 10/23] video: vga16fb: Only probe for EGA and VGA 16 color graphic cards Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 11/23] media: uvcvideo: fix division by zero at stream start Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 12/23] rtlwifi: rtl8192cu: Fix WARNING when calling local_irq_restore() with interrupts enabled Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 13/23] firmware: qemu_fw_cfg: fix sysfs information leak Greg Kroah-Hartman
2022-01-18 16:05 ` Greg Kroah-Hartman [this message]
2022-01-18 16:05 ` [PATCH 5.10 15/23] firmware: qemu_fw_cfg: fix kobject leak in probe error path Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 16/23] KVM: x86: remove PMU FIXED_CTR3 from msrs_to_save_all Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 17/23] ALSA: hda/realtek: Add speaker fixup for some Yoga 15ITL5 devices Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 18/23] ALSA: hda/realtek - Fix silent output on Gigabyte X570 Aorus Master after reboot from Windows Greg Kroah-Hartman
2022-01-18 16:05 ` [PATCH 5.10 19/23] ALSA: hda: ALC287: Add Lenovo IdeaPad Slim 9i 14ITL5 speaker quirk Greg Kroah-Hartman
2022-01-18 16:06 ` [PATCH 5.10 20/23] ALSA: hda/realtek: Add quirk for Legion Y9000X 2020 Greg Kroah-Hartman
2022-01-18 16:06 ` [PATCH 5.10 21/23] ALSA: hda/realtek: Re-order quirk entries for Lenovo Greg Kroah-Hartman
2022-01-18 16:06 ` [PATCH 5.10 22/23] powerpc/pseries: Get entry and uaccess flush required bits from H_GET_CPU_CHARACTERISTICS Greg Kroah-Hartman
2022-01-18 16:06 ` [PATCH 5.10 23/23] mtd: fixup CFI on ixp4xx Greg Kroah-Hartman
2022-01-18 17:35 ` [PATCH 5.10 00/23] 5.10.93-rc1 review Pavel Machek
2022-01-18 18:18 ` Greg Kroah-Hartman
2022-01-18 19:24 ` Florian Fainelli
2022-01-18 22:22 ` Shuah Khan
2022-01-19 10:35 ` Naresh Kamboju
2022-01-20 0:43 ` Guenter Roeck
2022-01-20 1:23 ` Samuel Zou
2022-01-21 15:02 ` Sudip Mukherjee
2022-01-21 15:52 ` Greg Kroah-Hartman
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