linux/lib, branch v6.8

iov_iter: get rid of 'copy_mc' flag

2024-03-06T09:52:12Z

This flag is only set by one single user: the magical core dumping code that looks up user pages one by one, and then writes them out using their kernel addresses (by using a BVEC_ITER). That actually ends up being a huge problem, because while we do use copy_mc_to_kernel() for this case and it is able to handle the possible machine checks involved, nothing else is really ready to handle the failures caused by the machine check. In particular, as reported by Tong Tiangen, we don't actually support fault_in_iov_iter_readable() on a machine check area. As a result, the usual logic for writing things to a file under a filesystem lock, which involves doing a copy with page faults disabled and then if that fails trying to fault pages in without holding the locks with fault_in_iov_iter_readable() does not work at all. We could decide to always just make the MC copy "succeed" (and filling the destination with zeroes), and that would then create a core dump file that just ignores any machine checks. But honestly, this single special case has been problematic before, and means that all the normal iov_iter code ends up slightly more complex and slower. See for example commit c9eec08bac96 ("iov_iter: Don't deal with iter->copy_mc in memcpy_from_iter_mc()") where David Howells re-organized the code just to avoid having to check the 'copy_mc' flags inside the inner iov_iter loops. So considering that we have exactly one user, and that one user is a non-critical special case that doesn't actually ever trigger in real life (Tong found this with manual error injection), the sane solution is to just decide that the onus on handling the machine check lines on that user instead. Ergo, do the copy_mc_to_kernel() in the core dump logic itself, copying the user data to a stable kernel page before writing it out. Fixes: f1982740f5e7 ("iov_iter: Convert iterate*() to inline funcs") Signed-off-by: Linus Torvalds Signed-off-by: Tong Tiangen Link: https://lore.kernel.org/r/20240305133336.3804360-1-tongtiangen@huawei.com Link: https://lore.kernel.org/all/4e80924d-9c85-f13a-722a-6a5d2b1c225a@huawei.com/ Tested-by: David Howells Reviewed-by: David Howells Reviewed-by: Jens Axboe Reported-by: Tong Tiangen Signed-off-by: Christian Brauner

Merge tag 'net-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-02-29T20:40:20Z

Pull networking fixes from Jakub Kicinski: "Including fixes from bluetooth, WiFi and netfilter. We have one outstanding issue with the stmmac driver, which may be a LOCKDEP false positive, not a blocker. Current release - regressions: - netfilter: nf_tables: re-allow NFPROTO_INET in nft_(match/target)_validate() - eth: ionic: fix error handling in PCI reset code Current release - new code bugs: - eth: stmmac: complete meta data only when enabled, fix null-deref - kunit: fix again checksum tests on big endian CPUs Previous releases - regressions: - veth: try harder when allocating queue memory - Bluetooth: - hci_bcm4377: do not mark valid bd_addr as invalid - hci_event: fix handling of HCI_EV_IO_CAPA_REQUEST Previous releases - always broken: - info leak in __skb_datagram_iter() on netlink socket - mptcp: - map v4 address to v6 when destroying subflow - fix potential wake-up event loss due to sndbuf auto-tuning - fix double-free on socket dismantle - wifi: nl80211: reject iftype change with mesh ID change - fix small out-of-bound read when validating netlink be16/32 types - rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back - ipv6: fix potential "struct net" ref-leak in inet6_rtm_getaddr() - ip_tunnel: prevent perpetual headroom growth with huge number of tunnels on top of each other - mctp: fix skb leaks on error paths of mctp_local_output() - eth: ice: fixes for DPLL state reporting - dpll: rely on rcu for netdev_dpll_pin() to prevent UaF - eth: dpaa: accept phy-interface-type = '10gbase-r' in the device tree" * tag 'net-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (73 commits) dpll: fix build failure due to rcu_dereference_check() on unknown type kunit: Fix again checksum tests on big endian CPUs tls: fix use-after-free on failed backlog decryption tls: separate no-async decryption request handling from async tls: fix peeking with sync+async decryption tls: decrement decrypt_pending if no async completion will be called gtp: fix use-after-free and null-ptr-deref in gtp_newlink() net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames igb: extend PTP timestamp adjustments to i211 rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back tools: ynl: fix handling of multiple mcast groups selftests: netfilter: add bridge conntrack + multicast test case netfilter: bridge: confirm multicast packets before passing them up the stack netfilter: nf_tables: allow NFPROTO_INET in nft_(match/target)_validate() Bluetooth: qca: Fix triggering coredump implementation Bluetooth: hci_qca: Set BDA quirk bit if fwnode exists in DT Bluetooth: qca: Fix wrong event type for patch config command Bluetooth: Enforce validation on max value of connection interval Bluetooth: hci_event: Fix handling of HCI_EV_IO_CAPA_REQUEST Bluetooth: mgmt: Fix limited discoverable off timeout ...

kunit: Fix again checksum tests on big endian CPUs

2024-02-29T17:16:02Z

Commit b38460bc463c ("kunit: Fix checksum tests on big endian CPUs") fixed endianness issues with kunit checksum tests, but then commit 6f4c45cbcb00 ("kunit: Add tests for csum_ipv6_magic and ip_fast_csum") introduced new issues on big endian CPUs. Those issues are once again reflected by the warnings reported by sparse. So, fix them with the same approach, perform proper conversion in order to support both little and big endian CPUs. Once the conversions are properly done and the right types used, the sparse warnings are cleared as well. Reported-by: Erhard Furtner Fixes: 6f4c45cbcb00 ("kunit: Add tests for csum_ipv6_magic and ip_fast_csum") Signed-off-by: Christophe Leroy Tested-by: Charlie Jenkins Tested-by: Guenter Roeck Acked-by: Paolo Abeni Acked-by: Palmer Dabbelt Link: https://lore.kernel.org/r/73df3a9e95c2179119398ad1b4c84cdacbd8dfb6.1708684443.git.christophe.leroy@csgroup.eu Signed-off-by: Jakub Kicinski

stackdepot: use variable size records for non-evictable entries

2024-02-24T01:27:12Z

With the introduction of stack depot evictions, each stack record is now fixed size, so that future reuse after an eviction can safely store differently sized stack traces. In all cases that do not make use of evictions, this wastes lots of space. Fix it by re-introducing variable size stack records (up to the max allowed size) for entries that will never be evicted. We know if an entry will never be evicted if the flag STACK_DEPOT_FLAG_GET is not provided, since a later stack_depot_put() attempt is undefined behavior. With my current kernel config that enables KASAN and also SLUB owner tracking, I observe (after a kernel boot) a whopping reduction of 296 stack depot pools, which translates into 4736 KiB saved. The savings here are from SLUB owner tracking only, because KASAN generic mode still uses refcounting. Before: pools: 893 allocations: 29841 frees: 6524 in_use: 23317 freelist_size: 3454 After: pools: 597 refcounted_allocations: 17547 refcounted_frees: 6477 refcounted_in_use: 11070 freelist_size: 3497 persistent_count: 12163 persistent_bytes: 1717008 [elver@google.com: fix -Wstringop-overflow warning] Link: https://lore.kernel.org/all/20240201135747.18eca98e@canb.auug.org.au/ Link: https://lkml.kernel.org/r/20240201090434.1762340-1-elver@google.com Link: https://lore.kernel.org/all/CABXGCsOzpRPZGg23QqJAzKnqkZPKzvieeg=W7sgjgi3q0pBo0g@mail.gmail.com/ Link: https://lkml.kernel.org/r/20240129100708.39460-1-elver@google.com Link: https://lore.kernel.org/all/CABXGCsOzpRPZGg23QqJAzKnqkZPKzvieeg=W7sgjgi3q0pBo0g@mail.gmail.com/ Fixes: 108be8def46e ("lib/stackdepot: allow users to evict stack traces") Signed-off-by: Marco Elver Reviewed-by: Andrey Konovalov Tested-by: Mikhail Gavrilov Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Vincenzo Frascino Cc: Vlastimil Babka Signed-off-by: Andrew Morton

netlink: add nla be16/32 types to minlen array

2024-02-23T03:01:55Z

BUG: KMSAN: uninit-value in nla_validate_range_unsigned lib/nlattr.c:222 [inline] BUG: KMSAN: uninit-value in nla_validate_int_range lib/nlattr.c:336 [inline] BUG: KMSAN: uninit-value in validate_nla lib/nlattr.c:575 [inline] BUG: KMSAN: uninit-value in __nla_validate_parse+0x2e20/0x45c0 lib/nlattr.c:631 nla_validate_range_unsigned lib/nlattr.c:222 [inline] nla_validate_int_range lib/nlattr.c:336 [inline] validate_nla lib/nlattr.c:575 [inline] ... The message in question matches this policy: [NFTA_TARGET_REV] = NLA_POLICY_MAX(NLA_BE32, 255), but because NLA_BE32 size in minlen array is 0, the validation code will read past the malformed (too small) attribute. Note: Other attributes, e.g. BITFIELD32, SINT, UINT.. are also missing: those likely should be added too. Reported-by: syzbot+3f497b07aa3baf2fb4d0@syzkaller.appspotmail.com Reported-by: xingwei lee Closes: https://lore.kernel.org/all/CABOYnLzFYHSnvTyS6zGa-udNX55+izqkOt2sB9WDqUcEGW6n8w@mail.gmail.com/raw Fixes: ecaf75ffd5f5 ("netlink: introduce bigendian integer types") Signed-off-by: Florian Westphal Link: https://lore.kernel.org/r/20240221172740.5092-1-fw@strlen.de Signed-off-by: Jakub Kicinski

lib/Kconfig.debug: TEST_IOV_ITER depends on MMU

2024-02-20T22:20:48Z

Trying to run the iov_iter unit test on a nommu system such as the qemu kc705-nommu emulation results in a crash. KTAP version 1 # Subtest: iov_iter # module: kunit_iov_iter 1..9 BUG: failure at mm/nommu.c:318/vmap()! Kernel panic - not syncing: BUG! The test calls vmap() directly, but vmap() is not supported on nommu systems, causing the crash. TEST_IOV_ITER therefore needs to depend on MMU. Link: https://lkml.kernel.org/r/20240208153010.1439753-1-linux@roeck-us.net Fixes: 2d71340ff1d4 ("iov_iter: Kunit tests for copying to/from an iterator") Signed-off-by: Guenter Roeck Cc: David Howells Cc: Signed-off-by: Andrew Morton

Merge tag 'driver-core-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2024-02-17T16:56:41Z

Pull driver core fixes from Greg KH: "Here are some driver core fixes, a kobject fix, and a documentation update for 6.8-rc5. In detail these changes are: - devlink fixes for reported issues with 6.8-rc1 - topology scheduling regression fix that has been reported by many - kobject loosening of checks change in -rc1 is now reverted as some codepaths seemed to need the checks - documentation update for the CVE process. Has been reviewed by many, the last minute change to the document was to bring the .rst format back into the the new style rules, the contents did not change. All of these, except for the documentation update, have been in linux-next for over a week. The documentation update has been reviewed for weeks by a group of developers, and in public for a week and the wording has stabilized for now. If future changes are needed, we can do so before 6.8-final is out (or anytime after that)" * tag 'driver-core-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: Documentation: Document the Linux Kernel CVE process Revert "kobject: Remove redundant checks for whether ktype is NULL" driver core: fw_devlink: Improve logs for cycle detection driver core: fw_devlink: Improve detection of overlapping cycles driver core: Fix device_link_flag_is_sync_state_only() topology: Set capacity_freq_ref in all cases

Merge tag 'trace-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-02-16T18:33:51Z

Pull tracing fixes from Steven Rostedt: - Fix the #ifndef that didn't have the 'CONFIG_' prefix on HAVE_DYNAMIC_FTRACE_WITH_REGS The fix to have dynamic trampolines work with x86 broke arm64 as the config used in the #ifdef was HAVE_DYNAMIC_FTRACE_WITH_REGS and not CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which removed the fix that the previous fix was to fix. - Fix tracing_on state The code to test if "tracing_on" is set incorrectly used ring_buffer_record_is_on() which returns false if the ring buffer isn't able to be written to. But the ring buffer disable has several bits that disable it. One is internal disabling which is used for resizing and other modifications of the ring buffer. But the "tracing_on" user space visible flag should only report if tracing is actually on and not internally disabled, as this can cause confusion as writing "1" when it is disabled will not enable it. Instead use ring_buffer_record_is_set_on() which shows the user space visible settings. - Fix a false positive kmemleak on saved cmdlines Now that the saved_cmdlines structure is allocated via alloc_page() and not via kmalloc() it has become invisible to kmemleak. The allocation done to one of its pointers was flagged as a dangling allocation leak. Make kmemleak aware of this allocation and free. - Fix synthetic event dynamic strings An update that cleaned up the synthetic event code removed the return value of trace_string(), and had it return zero instead of the length, causing dynamic strings in the synthetic event to always have zero size. - Clean up documentation and header files for seq_buf * tag 'trace-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: seq_buf: Fix kernel documentation seq_buf: Don't use "proxy" headers tracing/synthetic: Fix trace_string() return value tracing: Inform kmemleak of saved_cmdlines allocation tracing: Use ring_buffer_record_is_set_on() in tracer_tracing_is_on() tracing: Fix HAVE_DYNAMIC_FTRACE_WITH_REGS ifdef

seq_buf: Fix kernel documentation

2024-02-15T17:17:28Z

There are plenty of issues with the kernel documentation here: - misspelled word "sequence" - different style of returned value descriptions - missed Return sections - unaligned style of ASCII / NUL-terminated / etc - wrong function references Fix all these. Link: https://lkml.kernel.org/r/20240215152506.598340-1-andriy.shevchenko@linux.intel.com Cc: Andrew Morton Signed-off-by: Andy Shevchenko Reviewed-by: Randy Dunlap Signed-off-by: Steven Rostedt (Google)

seq_buf: Don't use "proxy" headers

2024-02-15T17:16:46Z

Update header inclusions to follow IWYU (Include What You Use) principle. Link: https://lkml.kernel.org/r/20240215142255.400264-1-andriy.shevchenko@linux.intel.com Cc: "Matthew Wilcox (Oracle)" Cc: Andrew Morton Signed-off-by: Andy Shevchenko Signed-off-by: Steven Rostedt (Google)