kernel/linux.git/lib, branch v5.4.232

netlink: prevent potential spectre v1 gadgets

2023-02-06T06:52:45+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

lockref: stop doing cpu_relax in the cmpxchg loop

2023-02-06T06:52:42+00:00

[ Upstream commit f5fe24ef17b5fbe6db49534163e77499fb10ae8c ] On the x86-64 architecture even a failing cmpxchg grants exclusive access to the cacheline, making it preferable to retry the failed op immediately instead of stalling with the pause instruction. To illustrate the impact, below are benchmark results obtained by running various will-it-scale tests on top of the 6.2-rc3 kernel and Cascade Lake (2 sockets * 24 cores * 2 threads) CPU. All results in ops/s. Note there is some variance in re-runs, but the code is consistently faster when contention is present. open3 ("Same file open/close"): proc stock no-pause 1 805603 814942 (+%1) 2 1054980 1054781 (-0%) 8 1544802 1822858 (+18%) 24 1191064 2199665 (+84%) 48 851582 1469860 (+72%) 96 609481 1427170 (+134%) fstat2 ("Same file fstat"): proc stock no-pause 1 3013872 3047636 (+1%) 2 4284687 4400421 (+2%) 8 3257721 5530156 (+69%) 24 2239819 5466127 (+144%) 48 1701072 5256609 (+209%) 96 1269157 6649326 (+423%) Additionally, a kernel with a private patch to help access() scalability: access2 ("Same file access"): proc stock patched patched +nopause 24 2378041 2005501 5370335 (-15% / +125%) That is, fixing the problems in access itself *reduces* scalability after the cacheline ping-pong only happens in lockref with the pause instruction. Note that fstat and access benchmarks are not currently integrated into will-it-scale, but interested parties can find them in pull requests to said project. Code at hand has a rather tortured history. First modification showed up in commit d472d9d98b46 ("lockref: Relax in cmpxchg loop"), written with Itanium in mind. Later it got patched up to use an arch-dependent macro to stop doing it on s390 where it caused a significant regression. Said macro had undergone revisions and was ultimately eliminated later, going back to cpu_relax. While I intended to only remove cpu_relax for x86-64, I got the following comment from Linus: I would actually prefer just removing it entirely and see if somebody else hollers. You have the numbers to prove it hurts on real hardware, and I don't think we have any numbers to the contrary. So I think it's better to trust the numbers and remove it as a failure, than say "let's just remove it on x86-64 and leave everybody else with the potentially broken code" Additionally, Will Deacon (maintainer of the arm64 port, one of the architectures previously benchmarked): So, from the arm64 side of the fence, I'm perfectly happy just removing the cpu_relax() calls from lockref. As such, come back full circle in history and whack it altogether. Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/all/CAGudoHHx0Nqg6DE70zAVA75eV-HXfWyhVMWZ-aSeOofkA_=WdA@mail.gmail.com/ Acked-by: Tony Luck # ia64 Acked-by: Nicholas Piggin # powerpc Acked-by: Will Deacon # arm64 Acked-by: Peter Zijlstra Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

mm/highmem: Lift memcpy_[to|from]_page to core

2023-01-18T10:41:55+00:00

[ Upstream commit bb90d4bc7b6a536b2e4db45f4763e467c2008251 ] Working through a conversion to a call kmap_local_page() instead of kmap() revealed many places where the pattern kmap/memcpy/kunmap occurred. Eric Biggers, Matthew Wilcox, Christoph Hellwig, Dan Williams, and Al Viro all suggested putting this code into helper functions. Al Viro further pointed out that these functions already existed in the iov_iter code.[1] Various locations for the lifted functions were considered. Headers like mm.h or string.h seem ok but don't really portray the functionality well. pagemap.h made some sense but is for page cache functionality.[2] Another alternative would be to create a new header for the promoted memcpy functions, but it masks the fact that these are designed to copy to/from pages using the kernel direct mappings and complicates matters with a new header. Placing these functions in 'highmem.h' is suboptimal especially with the changes being proposed in the functionality of kmap. From a caller perspective including/using 'highmem.h' implies that the functions defined in that header are only required when highmem is in use which is increasingly not the case with modern processors. However, highmem.h is where all the current functions like this reside (zero_user(), clear_highpage(), clear_user_highpage(), copy_user_highpage(), and copy_highpage()). So it makes the most sense even though it is distasteful for some.[3] Lift memcpy_to_page() and memcpy_from_page() to pagemap.h. [1] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/ https://lore.kernel.org/lkml/20201013112544.GA5249@infradead.org/ [2] https://lore.kernel.org/lkml/20201208122316.GH7338@casper.infradead.org/ [3] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/#t https://lore.kernel.org/lkml/20201208163814.GN1563847@iweiny-DESK2.sc.intel.com/ Cc: Boris Pismenny Cc: Or Gerlitz Cc: Dave Hansen Suggested-by: Matthew Wilcox Suggested-by: Christoph Hellwig Suggested-by: Dan Williams Suggested-by: Al Viro Suggested-by: Eric Biggers Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Ira Weiny Signed-off-by: David Sterba Stable-dep-of: 956510c0c743 ("fs: ext4: initialize fsdata in pagecache_write()") Signed-off-by: Sasha Levin

test_firmware: fix memory leak in test_firmware_init()

2023-01-18T10:41:23+00:00

[ Upstream commit 7610615e8cdb3f6f5bbd9d8e7a5d8a63e3cabf2e ] When misc_register() failed in test_firmware_init(), the memory pointed by test_fw_config->name is not released. The memory leak information is as follows: unreferenced object 0xffff88810a34cb00 (size 32): comm "insmod", pid 7952, jiffies 4294948236 (age 49.060s) hex dump (first 32 bytes): 74 65 73 74 2d 66 69 72 6d 77 61 72 65 2e 62 69 test-firmware.bi 6e 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 n............... backtrace: [] __kmalloc_node_track_caller+0x4b/0xc0 [] kstrndup+0x46/0xc0 [] __test_firmware_config_init+0x29/0x380 [test_firmware] [] 0xffffffffa040f068 [] do_one_initcall+0x141/0x780 [] do_init_module+0x1c3/0x630 [] load_module+0x623e/0x76a0 [] __do_sys_finit_module+0x181/0x240 [] do_syscall_64+0x39/0xb0 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: c92316bf8e94 ("test_firmware: add batched firmware tests") Signed-off-by: Zhengchao Shao Acked-by: Luis Chamberlain Link: https://lore.kernel.org/r/20221119035721.18268-1-shaozhengchao@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

lib/notifier-error-inject: fix error when writing -errno to debugfs file

2023-01-18T10:40:55+00:00

[ Upstream commit f883c3edd2c432a2931ec8773c70a570115a50fe ] The simple attribute files do not accept a negative value since the commit 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()"). This restores the previous behaviour by using newly introduced DEFINE_SIMPLE_ATTRIBUTE_SIGNED instead of DEFINE_SIMPLE_ATTRIBUTE. Link: https://lkml.kernel.org/r/20220919172418.45257-3-akinobu.mita@gmail.com Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by: Akinobu Mita Reported-by: Zhao Gongyi Reviewed-by: David Hildenbrand Reviewed-by: Greg Kroah-Hartman Cc: Alexander Viro Cc: Jonathan Corbet Cc: Oscar Salvador Cc: Rafael J. Wysocki Cc: Shuah Khan Cc: Wei Yongjun Cc: Yicong Yang Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

lib/fonts: fix undefined behavior in bit shift for get_default_font

2023-01-18T10:40:54+00:00

[ Upstream commit 6fe888c4d2fb174408e4540bb2d5602b9f507f90 ] Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in lib/fonts/fonts.c:139:20 left shift of 1 by 31 places cannot be represented in type 'int' dump_stack_lvl+0x7d/0xa5 dump_stack+0x15/0x1b ubsan_epilogue+0xe/0x4e __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c get_default_font+0x1c7/0x1f0 fbcon_startup+0x347/0x3a0 do_take_over_console+0xce/0x270 do_fbcon_takeover+0xa1/0x170 do_fb_registered+0x2a8/0x340 fbcon_fb_registered+0x47/0xe0 register_framebuffer+0x294/0x4a0 __drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper] drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper] drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper] drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper] bochs_pci_probe+0x6ca/0x772 [bochs] local_pci_probe+0x4d/0xb0 pci_device_probe+0x119/0x320 really_probe+0x181/0x550 __driver_probe_device+0xc6/0x220 driver_probe_device+0x32/0x100 __driver_attach+0x195/0x200 bus_for_each_dev+0xbb/0x120 driver_attach+0x27/0x30 bus_add_driver+0x22e/0x2f0 driver_register+0xa9/0x190 __pci_register_driver+0x90/0xa0 bochs_pci_driver_init+0x52/0x1000 [bochs] do_one_initcall+0x76/0x430 do_init_module+0x61/0x28a load_module+0x1f82/0x2e50 __do_sys_finit_module+0xf8/0x190 __x64_sys_finit_module+0x23/0x30 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Link: https://lkml.kernel.org/r/20221031113829.4183153-1-cuigaosheng1@huawei.com Fixes: c81f717cb9e0 ("fbcon: Fix typo and bogus logic in get_default_font") Signed-off-by: Gaosheng Cui Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled

2022-12-08T10:23:05+00:00

[ Upstream commit 152fe65f300e1819d59b80477d3e0999b4d5d7d2 ] When enabled, KASAN enlarges function's stack-frames. Pushing quite a few over the current threshold. This can mainly be seen on 32-bit architectures where the present limit (when !GCC) is a lowly 1024-Bytes. Link: https://lkml.kernel.org/r/20221125120750.3537134-3-lee@kernel.org Signed-off-by: Lee Jones Acked-by: Arnd Bergmann Cc: Alex Deucher Cc: "Christian König" Cc: Daniel Vetter Cc: David Airlie Cc: Harry Wentland Cc: Leo Li Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: "Pan, Xinhui" Cc: Rodrigo Siqueira Cc: Thomas Zimmermann Cc: Tom Rix Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

parisc: Increase FRAME_WARN to 2048 bytes on parisc

2022-12-08T10:23:05+00:00

[ Upstream commit 8d192bec534bd5b778135769a12e5f04580771f7 ] PA-RISC uses a much bigger frame size for functions than other architectures. So increase it to 2048 for 32- and 64-bit kernels. This fixes e.g. a warning in lib/xxhash.c. Reported-by: kernel test robot Signed-off-by: Helge Deller Stable-dep-of: 152fe65f300e ("Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled") Signed-off-by: Sasha Levin

xtensa: increase size of gcc stack frame check

2022-12-08T10:23:05+00:00

[ Upstream commit 867050247e295cf20fce046a92a7e6491fcfe066 ] xtensa frame size is larger than the frame size for almost all other architectures. This results in more than 50 "the frame size of is larger than 1024 bytes" errors when trying to build xtensa:allmodconfig. Increase frame size for xtensa to 1536 bytes to avoid compile errors due to frame size limits. Link: https://lkml.kernel.org/r/20210912025235.3514761-1-linux@roeck-us.net Signed-off-by: Guenter Roeck Reviewed-by: Max Filippov Cc: Chris Zankel Cc: David Laight Cc: Masahiro Yamada Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Stable-dep-of: 152fe65f300e ("Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled") Signed-off-by: Sasha Levin

parisc: Increase size of gcc stack frame check

2022-12-08T10:23:05+00:00

[ Upstream commit 55b70eed81cba1331773d4aaf5cba2bb07475cd8 ] parisc uses much bigger frames than other architectures, so increase the stack frame check value to avoid compiler warnings. Cc: Arnd Bergmann Cc: Abd-Alrhman Masalkhi Cc: Christoph Hellwig Signed-off-by: Helge Deller Stable-dep-of: 152fe65f300e ("Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled") Signed-off-by: Sasha Levin