CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2022-48870 – tty: fix possible null-ptr-defer in spk_ttyio_release
https://notcve.org/view.php?id=CVE-2022-48870
In the Linux kernel, the following vulnerability has been resolved: tty: fix possible null-ptr-defer in spk_ttyio_release Run the following tests on the qemu platform: syzkaller:~# modprobe speakup_audptr input: Speakup as /devices/virtual/input/input4 initialized device: /dev/synth, node (MAJOR 10, MINOR 125) speakup 3.1.6: initialized synth name on entry is: (null) synth probe spk_ttyio_initialise_ldisc failed because tty_kopen_exclusive returned failed (errno -16), then remove the module, we will get a null-ptr-defer problem, as follow: syzkaller:~# modprobe -r speakup_audptr releasing synth audptr BUG: kernel NULL pointer dereference, address: 0000000000000080 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 2 PID: 204 Comm: modprobe Not tainted 6.1.0-rc6-dirty #1 RIP: 0010:mutex_lock+0x14/0x30 Call Trace: <TASK> spk_ttyio_release+0x19/0x70 [speakup] synth_release.part.6+0xac/0xc0 [speakup] synth_remove+0x56/0x60 [speakup] __x64_sys_delete_module+0x156/0x250 ? fpregs_assert_state_consistent+0x1d/0x50 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> Modules linked in: speakup_audptr(-) speakup Dumping ftrace buffer: in_synth->dev was not initialized during modprobe, so we add check for in_synth->dev to fix this bug. • https://git.kernel.org/stable/c/4f2a81f3a88217e7340b2cab5c0a5ebd0112514c https://git.kernel.org/stable/c/2da67bff29ab49caafb0766e8b8383b735ff796f https://git.kernel.org/stable/c/64152e05a4de3ebf59f1740a0985a6d5fba0c77b https://git.kernel.org/stable/c/5abbeebd8296c2301023b8dc4b5a6c0d5229b4f5 •
CVSS: -EPSS: 0%CPEs: 5EXPL: 0CVE-2022-48869 – USB: gadgetfs: Fix race between mounting and unmounting
https://notcve.org/view.php?id=CVE-2022-48869
In the Linux kernel, the following vulnerability has been resolved: USB: gadgetfs: Fix race between mounting and unmounting The syzbot fuzzer and Gerald Lee have identified a use-after-free bug in the gadgetfs driver, involving processes concurrently mounting and unmounting the gadgetfs filesystem. In particular, gadgetfs_fill_super() can race with gadgetfs_kill_sb(), causing the latter to deallocate the_device while the former is using it. The output from KASAN says, in part: BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline] BUG: KASAN: use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline] BUG: KASAN: use-after-free in __refcount_sub_and_test include/linux/refcount.h:272 [inline] BUG: KASAN: use-after-free in __refcount_dec_and_test include/linux/refcount.h:315 [inline] BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:333 [inline] BUG: KASAN: use-after-free in put_dev drivers/usb/gadget/legacy/inode.c:159 [inline] BUG: KASAN: use-after-free in gadgetfs_kill_sb+0x33/0x100 drivers/usb/gadget/legacy/inode.c:2086 Write of size 4 at addr ffff8880276d7840 by task syz-executor126/18689 CPU: 0 PID: 18689 Comm: syz-executor126 Not tainted 6.1.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> ... atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline] __refcount_sub_and_test include/linux/refcount.h:272 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] put_dev drivers/usb/gadget/legacy/inode.c:159 [inline] gadgetfs_kill_sb+0x33/0x100 drivers/usb/gadget/legacy/inode.c:2086 deactivate_locked_super+0xa7/0xf0 fs/super.c:332 vfs_get_super fs/super.c:1190 [inline] get_tree_single+0xd0/0x160 fs/super.c:1207 vfs_get_tree+0x88/0x270 fs/super.c:1531 vfs_fsconfig_locked fs/fsopen.c:232 [inline] The simplest solution is to ensure that gadgetfs_fill_super() and gadgetfs_kill_sb() are serialized by making them both acquire a new mutex. • https://git.kernel.org/stable/c/e5d82a7360d124ae1a38c2a5eac92ba49b125191 https://git.kernel.org/stable/c/9a39f4626b361ee7aa10fd990401c37ec3b466ae https://git.kernel.org/stable/c/856e4b5e53f21edbd15d275dde62228dd94fb2b4 https://git.kernel.org/stable/c/a2e075f40122d8daf587db126c562a67abd69cf9 https://git.kernel.org/stable/c/616fd34d017000ecf9097368b13d8a266f4920b3 https://git.kernel.org/stable/c/d18dcfe9860e842f394e37ba01ca9440ab2178f4 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2022-48868 – dmaengine: idxd: Let probe fail when workqueue cannot be enabled
https://notcve.org/view.php?id=CVE-2022-48868
In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Let probe fail when workqueue cannot be enabled The workqueue is enabled when the appropriate driver is loaded and disabled when the driver is removed. When the driver is removed it assumes that the workqueue was enabled successfully and proceeds to free allocations made during workqueue enabling. Failure during workqueue enabling does not prevent the driver from being loaded. This is because the error path within drv_enable_wq() returns success unless a second failure is encountered during the error path. By returning success it is possible to load the driver even if the workqueue cannot be enabled and allocations that do not exist are attempted to be freed during driver remove. Some examples of problematic flows: (a) idxd_dmaengine_drv_probe() -> drv_enable_wq() -> idxd_wq_request_irq(): In above flow, if idxd_wq_request_irq() fails then idxd_wq_unmap_portal() is called on error exit path, but drv_enable_wq() returns 0 because idxd_wq_disable() succeeds. The driver is thus loaded successfully. idxd_dmaengine_drv_remove()->drv_disable_wq()->idxd_wq_unmap_portal() Above flow on driver unload triggers the WARN in devm_iounmap() because the device resource has already been removed during error path of drv_enable_wq(). (b) idxd_dmaengine_drv_probe() -> drv_enable_wq() -> idxd_wq_request_irq(): In above flow, if idxd_wq_request_irq() fails then idxd_wq_init_percpu_ref() is never called to initialize the percpu counter, yet the driver loads successfully because drv_enable_wq() returns 0. idxd_dmaengine_drv_remove()->__idxd_wq_quiesce()->percpu_ref_kill(): Above flow on driver unload triggers a BUG when attempting to drop the initial ref of the uninitialized percpu ref: BUG: kernel NULL pointer dereference, address: 0000000000000010 Fix the drv_enable_wq() error path by returning the original error that indicates failure of workqueue enabling. • https://git.kernel.org/stable/c/1f2bb40337f0df1d9af80793e9fdacff7706e654 https://git.kernel.org/stable/c/0f150134dd795ffcd60b798a85ab737d8d010fb7 https://git.kernel.org/stable/c/99dc4520b74e7ca8e9dc9abe37a0b10b49467960 https://git.kernel.org/stable/c/b51b75f0604f17c0f6f3b6f68f1a521a5cc6b04f •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2022-48867 – dmaengine: idxd: Prevent use after free on completion memory
https://notcve.org/view.php?id=CVE-2022-48867
In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Prevent use after free on completion memory On driver unload any pending descriptors are flushed at the time the interrupt is freed: idxd_dmaengine_drv_remove() -> drv_disable_wq() -> idxd_wq_free_irq() -> idxd_flush_pending_descs(). If there are any descriptors present that need to be flushed this flow triggers a "not present" page fault as below: BUG: unable to handle page fault for address: ff391c97c70c9040 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page The address that triggers the fault is the address of the descriptor that was freed moments earlier via: drv_disable_wq()->idxd_wq_free_resources() Fix the use after free by freeing the descriptors after any possible usage. This is done after idxd_wq_reset() to ensure that the memory remains accessible during possible completion writes by the device. • https://git.kernel.org/stable/c/63c14ae6c161dec8ff3be49277edc75a769e054a https://git.kernel.org/stable/c/b9e8e3fcfec625fc1c2f68f684448aeeb882625b https://git.kernel.org/stable/c/1beeec45f9ac31eba52478379f70a5fa9c2ad005 •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2024-43882 – exec: Fix ToCToU between perm check and set-uid/gid usage
https://notcve.org/view.php?id=CVE-2024-43882
In the Linux kernel, the following vulnerability has been resolved: exec: Fix ToCToU between perm check and set-uid/gid usage When opening a file for exec via do_filp_open(), permission checking is done against the file's metadata at that moment, and on success, a file pointer is passed back. Much later in the execve() code path, the file metadata (specifically mode, uid, and gid) is used to determine if/how to set the uid and gid. However, those values may have changed since the permissions check, meaning the execution may gain unintended privileges. For example, if a file could change permissions from executable and not set-id: ---------x 1 root root 16048 Aug 7 13:16 target to set-id and non-executable: ---S------ 1 root root 16048 Aug 7 13:16 target it is possible to gain root privileges when execution should have been disallowed. While this race condition is rare in real-world scenarios, it has been observed (and proven exploitable) when package managers are updating the setuid bits of installed programs. Such files start with being world-executable but then are adjusted to be group-exec with a set-uid bit. For example, "chmod o-x,u+s target" makes "target" executable only by uid "root" and gid "cdrom", while also becoming setuid-root: -rwxr-xr-x 1 root cdrom 16048 Aug 7 13:16 target becomes: -rwsr-xr-- 1 root cdrom 16048 Aug 7 13:16 target But racing the chmod means users without group "cdrom" membership can get the permission to execute "target" just before the chmod, and when the chmod finishes, the exec reaches brpm_fill_uid(), and performs the setuid to root, violating the expressed authorization of "only cdrom group members can setuid to root". Re-check that we still have execute permissions in case the metadata has changed. • https://git.kernel.org/stable/c/d5c3c7e26275a2d83b894d30f7582a42853a958f https://git.kernel.org/stable/c/368f6985d46657b8b466a421dddcacd4051f7ada https://git.kernel.org/stable/c/15469d46ba34559bfe7e3de6659115778c624759 https://git.kernel.org/stable/c/9b424c5d4130d56312e2a3be17efb0928fec4d64 https://git.kernel.org/stable/c/f6cfc6bcfd5e1cf76115b6450516ea4c99897ae1 https://git.kernel.org/stable/c/d2a2a4714d80d09b0f8eb6438ab4224690b7121e https://git.kernel.org/stable/c/90dfbba89ad4f0d9c9744ecbb1adac4aa2ff4f3e https://git.kernel.org/stable/c/f50733b45d865f91db90919f8311e2127 •