kernel/linux.git/lib, branch v5.15.112

debugobject: Ensure pool refill (again)

2023-05-11T14:00:40+00:00

commit 0af462f19e635ad522f28981238334620881badc upstream. The recent fix to ensure atomicity of lookup and allocation inadvertently broke the pool refill mechanism. Prior to that change debug_objects_activate() and debug_objecs_assert_init() invoked debug_objecs_init() to set up the tracking object for statically initialized objects. That's not longer the case and debug_objecs_init() is now the only place which does pool refills. Depending on the number of statically initialized objects this can be enough to actually deplete the pool, which was observed by Ido via a debugobjects OOM warning. Restore the old behaviour by adding explicit refill opportunities to debug_objects_activate() and debug_objecs_assert_init(). Fixes: 63a759694eed ("debugobject: Prevent init race with static objects") Reported-by: Ido Schimmel Signed-off-by: Thomas Gleixner Tested-by: Ido Schimmel Link: https://lore.kernel.org/r/871qk05a9d.ffs@tglx Signed-off-by: Greg Kroah-Hartman

debugobject: Prevent init race with static objects

2023-05-11T14:00:25+00:00

[ Upstream commit 63a759694eed61025713b3e14dd827c8548daadc ] Statically initialized objects are usually not initialized via the init() function of the subsystem. They are special cased and the subsystem provides a function to validate whether an object which is not yet tracked by debugobjects is statically initialized. This means the object is started to be tracked on first use, e.g. activation. This works perfectly fine, unless there are two concurrent operations on that object. Schspa decoded the problem: T0 T1 debug_object_assert_init(addr) lock_hash_bucket() obj = lookup_object(addr); if (!obj) { unlock_hash_bucket(); - > preemption lock_subsytem_object(addr); activate_object(addr) lock_hash_bucket(); obj = lookup_object(addr); if (!obj) { unlock_hash_bucket(); if (is_static_object(addr)) init_and_track(addr); lock_hash_bucket(); obj = lookup_object(addr); obj->state = ACTIVATED; unlock_hash_bucket(); subsys function modifies content of addr, so static object detection does not longer work. unlock_subsytem_object(addr); if (is_static_object(addr)) <- Fails debugobject emits a warning and invokes the fixup function which reinitializes the already active object in the worst case. This race exists forever, but was never observed until mod_timer() got a debug_object_assert_init() added which is outside of the timer base lock held section right at the beginning of the function to cover the lockless early exit points too. Rework the code so that the lookup, the static object check and the tracking object association happens atomically under the hash bucket lock. This prevents the issue completely as all callers are serialized on the hash bucket lock and therefore cannot observe inconsistent state. Fixes: 3ac7fe5a4aab ("infrastructure to debug (dynamic) objects") Reported-by: syzbot+5093ba19745994288b53@syzkaller.appspotmail.com Debugged-by: Schspa Shi Signed-off-by: Thomas Gleixner Reviewed-by: Stephen Boyd Link: https://syzkaller.appspot.com/bug?id=22c8a5938eab640d1c6bcc0e3dc7be519d878462 Link: https://lore.kernel.org/lkml/20230303161906.831686-1-schspa@gmail.com Link: https://lore.kernel.org/r/87zg7dzgao.ffs@tglx Signed-off-by: Sasha Levin

kobject: Fix slab-out-of-bounds in fill_kobj_path()

2023-03-10T08:39:35+00:00

[ Upstream commit 3bb2a01caa813d3a1845d378bbe4169ef280d394 ] In kobject_get_path(), if kobj->name is changed between calls get_kobj_path_length() and fill_kobj_path() and the length becomes longer, then fill_kobj_path() will have an out-of-bounds bug. The actual current problem occurs when the ixgbe probe. In ixgbe_mii_bus_init(), if the length of netdev->dev.kobj.name length becomes longer, out-of-bounds will occur. cpu0 cpu1 ixgbe_probe register_netdev(netdev) netdev_register_kobject device_add kobject_uevent // Sending ADD events systemd-udevd // rename netdev dev_change_name device_rename kobject_rename ixgbe_mii_bus_init | mdiobus_register | __mdiobus_register | device_register | device_add | kobject_uevent | kobject_get_path | len = get_kobj_path_length // old name | path = kzalloc(len, gfp_mask); | kobj->name = name; /* name length becomes * longer */ fill_kobj_path /* kobj path length is * longer than path, * resulting in out of * bounds when filling path */ This is the kasan report: ================================================================== BUG: KASAN: slab-out-of-bounds in fill_kobj_path+0x50/0xc0 Write of size 7 at addr ff1100090573d1fd by task kworker/28:1/673 Workqueue: events work_for_cpu_fn Call Trace: dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x86/0x1e7 print_report+0x36/0x4f kasan_report+0xad/0x130 kasan_check_range+0x35/0x1c0 memcpy+0x39/0x60 fill_kobj_path+0x50/0xc0 kobject_get_path+0x5a/0xc0 kobject_uevent_env+0x140/0x460 device_add+0x5c7/0x910 __mdiobus_register+0x14e/0x490 ixgbe_probe.cold+0x441/0x574 [ixgbe] local_pci_probe+0x78/0xc0 work_for_cpu_fn+0x26/0x40 process_one_work+0x3b6/0x6a0 worker_thread+0x368/0x520 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 This reproducer triggers that bug: while: do rmmod ixgbe sleep 0.5 modprobe ixgbe sleep 0.5 When calling fill_kobj_path() to fill path, if the name length of kobj becomes longer, return failure and retry. This fixes the problem. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Hai Link: https://lore.kernel.org/r/20221220012143.52141-1-wanghai38@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

kobject: modify kobject_get_path() to take a const *

2023-03-10T08:39:35+00:00

[ Upstream commit 33a0a1e3b3d17445832177981dc7a1c6a5b009f8 ] kobject_get_path() does not modify the kobject passed to it, so make the pointer constant. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20221001165315.2690141-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 3bb2a01caa81 ("kobject: Fix slab-out-of-bounds in fill_kobj_path()") Signed-off-by: Sasha Levin

printf: fix errname.c list

2023-03-10T08:39:33+00:00

[ Upstream commit 0c2baf6509af1d11310ae4c1c839481a6e9a4bc4 ] On most architectures, gcc -Wextra warns about the list of error numbers containing both EDEADLK and EDEADLOCK: lib/errname.c:15:67: warning: initialized field overwritten [-Woverride-init] 15 | #define E(err) [err + BUILD_BUG_ON_ZERO(err <= 0 || err > 300)] = "-" #err | ^~~ lib/errname.c:172:2: note: in expansion of macro 'E' 172 | E(EDEADLK), /* EDEADLOCK */ | ^ On parisc, a similar error happens with -ECANCELLED, which is an alias for ECANCELED. Make the EDEADLK printing conditional on the number being distinct from EDEADLOCK, and remove the -ECANCELLED bit completely as it can never be hit. To ensure these are correct, add static_assert lines that verify all the remaining aliases are in fact identical to the canonical name. Fixes: 57f5677e535b ("printf: add support for printing symbolic error names") Cc: Petr Mladek Suggested-by: Rasmus Villemoes Acked-by: Uwe Kleine-König Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/all/20210514213456.745039-1-arnd@kernel.org/ Link: https://lore.kernel.org/all/20210927123409.1109737-1-arnd@kernel.org/ Signed-off-by: Arnd Bergmann Reviewed-by: Sergey Senozhatsky Acked-by: Rasmus Villemoes Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20230206194126.380350-1-arnd@kernel.org Signed-off-by: Sasha Levin

lib/mpi: Fix buffer overrun when SG is too long

2023-03-10T08:39:09+00:00

[ Upstream commit 7361d1bc307b926cbca214ab67b641123c2d6357 ] The helper mpi_read_raw_from_sgl sets the number of entries in the SG list according to nbytes. However, if the last entry in the SG list contains more data than nbytes, then it may overrun the buffer because it only allocates enough memory for nbytes. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Reported-by: Roberto Sassu Signed-off-by: Herbert Xu Reviewed-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

lib/Kconfig.debug: Allow BTF + DWARF5 with pahole 1.21+

2023-02-25T11:06:46+00:00

commit 42d9b379e3e1790eafb87c799c9edfd0b37a37c7 upstream. Commit 98cd6f521f10 ("Kconfig: allow explicit opt in to DWARF v5") prevented CONFIG_DEBUG_INFO_DWARF5 from being selected when CONFIG_DEBUG_INFO_BTF is enabled because pahole had issues with clang's DWARF5 info. This was resolved by [1], which is in pahole v1.21. Allow DEBUG_INFO_DWARF5 to be selected with DEBUG_INFO_BTF when using pahole v1.21 or newer. [1]: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=7d8e829f636f47aba2e1b6eda57e74d8e31f733c Signed-off-by: Nathan Chancellor Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220201205624.652313-6-nathan@kernel.org Signed-off-by: Matthias Maennich Signed-off-by: Greg Kroah-Hartman

lib/Kconfig.debug: Use CONFIG_PAHOLE_VERSION

2023-02-25T11:06:46+00:00

commit 6323c81350b73a4569cf52df85f80273faa64071 upstream. Now that CONFIG_PAHOLE_VERSION exists, use it in the definition of CONFIG_PAHOLE_HAS_SPLIT_BTF and CONFIG_PAHOLE_HAS_BTF_TAG to reduce the amount of duplication across the tree. Signed-off-by: Nathan Chancellor Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220201205624.652313-5-nathan@kernel.org [maennich: omitted patching non-existing config PAHOLE_HAS_BTF_TAG] Signed-off-by: Matthias Maennich Signed-off-by: Greg Kroah-Hartman

uaccess: Add speculation barrier to copy_from_user()

2023-02-25T11:06:44+00:00

commit 74e19ef0ff8061ef55957c3abd71614ef0f42f47 upstream. The results of "access_ok()" can be mis-speculated. The result is that you can end speculatively: if (access_ok(from, size)) // Right here even for bad from/size combinations. On first glance, it would be ideal to just add a speculation barrier to "access_ok()" so that its results can never be mis-speculated. But there are lots of system calls just doing access_ok() via "copy_to_user()" and friends (example: fstat() and friends). Those are generally not problematic because they do not _consume_ data from userspace other than the pointer. They are also very quick and common system calls that should not be needlessly slowed down. "copy_from_user()" on the other hand uses a user-controller pointer and is frequently followed up with code that might affect caches. Take something like this: if (!copy_from_user(&kernelvar, uptr, size)) do_something_with(kernelvar); If userspace passes in an evil 'uptr' that *actually* points to a kernel addresses, and then do_something_with() has cache (or other) side-effects, it could allow userspace to infer kernel data values. Add a barrier to the common copy_from_user() code to prevent mis-speculated values which happen after the copy. Also add a stub for architectures that do not define barrier_nospec(). This makes the macro usable in generic code. Since the barrier is now usable in generic code, the x86 #ifdef in the BPF code can also go away. Reported-by: Jordy Zomer Suggested-by: Linus Torvalds Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Acked-by: Daniel Borkmann # BPF bits Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

netlink: prevent potential spectre v1 gadgets

2023-02-01T07:27:26+00:00

[ Upstream commit f0950402e8c76e7dcb08563f1b4e8000fbc62455 ] Most netlink attributes are parsed and validated from __nla_validate_parse() or validate_nla() u16 type = nla_type(nla); if (type == 0 || type > maxtype) { /* error or continue */ } @type is then used as an array index and can be used as a Spectre v1 gadget. array_index_nospec() can be used to prevent leaking content of kernel memory to malicious users. This should take care of vast majority of netlink uses, but an audit is needed to take care of others where validation is not yet centralized in core netlink functions. Fixes: bfa83a9e03cf ("[NETLINK]: Type-safe netlink messages/attributes interface") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230119110150.2678537-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin