user/sven/linux.git/kernel/module.c, branch v5.3.4

modules: page-align module section allocations only for arches supporting strict module rwx

2019-08-21T08:43:56Z

We should keep the case of "#define debug_align(X) (X)" for all arches without CONFIG_HAS_STRICT_MODULE_RWX ability, which would save people, who are sensitive to system size, a lot of memory when using modules, especially for embedded systems. This is also the intention of the original #ifdef... statement and still valid for now. Note that this still keeps the effect of the fix of the following commit, 38f054d549a8 ("modules: always page-align module section allocations"), since when CONFIG_ARCH_HAS_STRICT_MODULE_RWX is enabled, module pages are aligned. Signed-off-by: He Zhe Signed-off-by: Jessica Yu

modules: always page-align module section allocations

2019-07-30T08:35:23Z

Some arches (e.g., arm64, x86) have moved towards non-executable module_alloc() allocations for security hardening reasons. That means that the module loader will need to set the text section of a module to executable, regardless of whether or not CONFIG_STRICT_MODULE_RWX is set. When CONFIG_STRICT_MODULE_RWX=y, module section allocations are always page-aligned to handle memory rwx permissions. On some arches with CONFIG_STRICT_MODULE_RWX=n however, when setting the module text to executable, the BUG_ON() in frob_text() gets triggered since module section allocations are not page-aligned when CONFIG_STRICT_MODULE_RWX=n. Since the set_memory_* API works with pages, and since we need to call set_memory_x() regardless of whether CONFIG_STRICT_MODULE_RWX is set, we might as well page-align all module section allocations for ease of managing rwx permissions of module sections (text, rodata, etc). Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n") Reported-by: Martin Kaiser Reported-by: Bartosz Golaszewski Tested-by: David Lechner Tested-by: Martin Kaiser Tested-by: Bartosz Golaszewski Signed-off-by: Jessica Yu

Merge tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

2019-07-18T19:06:57Z

Pull module updates from Jessica Yu: "Summary of modules changes for the 5.3 merge window: - Code fixes and cleanups - Fix bug where set_memory_x() wasn't being called when rodata=n - Fix bug where -EEXIST was being returned for going modules - Allow arches to override module_exit_section()" * tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: modules: fix compile error if don't have strict module rwx ARM: module: recognize unwind exit sections module: allow arch overrides for .exit section names modules: fix BUG when load module with rodata=n kernel/module: Fix mem leak in module_add_modinfo_attrs kernel: module: Use struct_size() helper kernel/module.c: Only return -EEXIST for modules that have finished loading

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2019-06-28T17:46:47Z

Pull rcu/next + tools/memory-model changes from Paul E. McKenney: - RCU flavor consolidation cleanups and optmizations - Documentation updates - Miscellaneous fixes - SRCU updates - RCU-sync flavor consolidation - Torture-test updates - Linux-kernel memory-consistency-model updates, most notably the addition of plain C-language accesses Signed-off-by: Ingo Molnar

modules: fix compile error if don't have strict module rwx

2019-06-26T17:27:59Z

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is not defined, we need stub for module_enable_nx() and module_enable_x(). If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is defined, but CONFIG_STRICT_MODULE_RWX is disabled, we need stub for module_enable_nx. Move frob_text() outside of the CONFIG_STRICT_MODULE_RWX, because it is needed anyway. Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n") Signed-off-by: Yang Yingliang Signed-off-by: Jessica Yu

module: allow arch overrides for .exit section names

2019-06-24T12:00:32Z

Some archs like ARM store unwind information for .exit.text in sections with unusual names. As this unwind information refers to .exit.text, it must not be loaded when .exit.text is not loaded (when CONFIG_MODULE_UNLOAD is unset); otherwise, loading a module can fail due to relocation failures. Signed-off-by: Matthias Schiffer Signed-off-by: Jessica Yu

modules: fix BUG when load module with rodata=n

2019-06-24T10:11:41Z

When loading a module with rodata=n, it causes an executing NX-protected page BUG. [ 32.379191] kernel tried to execute NX-protected page - exploit attempt? (uid: 0) [ 32.382917] BUG: unable to handle page fault for address: ffffffffc0005000 [ 32.385947] #PF: supervisor instruction fetch in kernel mode [ 32.387662] #PF: error_code(0x0011) - permissions violation [ 32.389352] PGD 240c067 P4D 240c067 PUD 240e067 PMD 421a52067 PTE 8000000421a53063 [ 32.391396] Oops: 0011 [#1] SMP PTI [ 32.392478] CPU: 7 PID: 2697 Comm: insmod Tainted: G O 5.2.0-rc5+ #202 [ 32.394588] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 32.398157] RIP: 0010:ko_test_init+0x0/0x1000 [ko_test] [ 32.399662] Code: Bad RIP value. [ 32.400621] RSP: 0018:ffffc900029f3ca8 EFLAGS: 00010246 [ 32.402171] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 32.404332] RDX: 00000000000004c7 RSI: 0000000000000cc0 RDI: ffffffffc0005000 [ 32.406347] RBP: ffffffffc0005000 R08: ffff88842fbebc40 R09: ffffffff810ede4a [ 32.408392] R10: ffffea00108e3480 R11: 0000000000000000 R12: ffff88842bee21a0 [ 32.410472] R13: 0000000000000001 R14: 0000000000000001 R15: ffffc900029f3e78 [ 32.412609] FS: 00007fb4f0c0a700(0000) GS:ffff88842fbc0000(0000) knlGS:0000000000000000 [ 32.414722] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 32.416290] CR2: ffffffffc0004fd6 CR3: 0000000421a90004 CR4: 0000000000020ee0 [ 32.418471] Call Trace: [ 32.419136] do_one_initcall+0x41/0x1df [ 32.420199] ? _cond_resched+0x10/0x40 [ 32.421433] ? kmem_cache_alloc_trace+0x36/0x160 [ 32.422827] do_init_module+0x56/0x1f7 [ 32.423946] load_module+0x1e67/0x2580 [ 32.424947] ? __alloc_pages_nodemask+0x150/0x2c0 [ 32.426413] ? map_vm_area+0x2d/0x40 [ 32.427530] ? __vmalloc_node_range+0x1ef/0x260 [ 32.428850] ? __do_sys_init_module+0x135/0x170 [ 32.430060] ? _cond_resched+0x10/0x40 [ 32.431249] __do_sys_init_module+0x135/0x170 [ 32.432547] do_syscall_64+0x43/0x120 [ 32.433853] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Because if rodata=n, set_memory_x() can't be called, fix this by calling set_memory_x in complete_formation(); Fixes: f2c65fb3221a ("x86/modules: Avoid breaking W^X while loading modules") Suggested-by: Jian Cheng Reviewed-by: Nadav Amit Signed-off-by: Yang Yingliang Signed-off-by: Jessica Yu

kernel/module: Fix mem leak in module_add_modinfo_attrs

2019-06-14T07:31:09Z

In module_add_modinfo_attrs if sysfs_create_file fails, we forget to free allocated modinfo_attrs and roll back the sysfs files. Fixes: 03e88ae1b13d ("[PATCH] fix module sysfs files reference counting") Reviewed-by: Miroslav Benes Signed-off-by: YueHaibing Signed-off-by: Jessica Yu

kernel: module: Use struct_size() helper

2019-06-07T08:56:32Z

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct module_sect_attrs { ... struct module_sect_attr attrs[0]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0] with: struct_size(sect_attrs, attrs, nloaded) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Jessica Yu

kernel/module.c: Only return -EEXIST for modules that have finished loading

2019-06-05T07:53:24Z

Microsoft HyperV disables the X86_FEATURE_SMCA bit on AMD systems, and linux guests boot with repeated errors: amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2) amd64_edac_mod: Unknown symbol amd_unregister_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_register_ecc_decoder (err -2) amd64_edac_mod: Unknown symbol amd_report_gart_errors (err -2) The warnings occur because the module code erroneously returns -EEXIST for modules that have failed to load and are in the process of being removed from the module list. module amd64_edac_mod has a dependency on module edac_mce_amd. Using modules.dep, systemd will load edac_mce_amd for every request of amd64_edac_mod. When the edac_mce_amd module loads, the module has state MODULE_STATE_UNFORMED and once the module load fails and the state becomes MODULE_STATE_GOING. Another request for edac_mce_amd module executes and add_unformed_module() will erroneously return -EEXIST even though the previous instance of edac_mce_amd has MODULE_STATE_GOING. Upon receiving -EEXIST, systemd attempts to load amd64_edac_mod, which fails because of unknown symbols from edac_mce_amd. add_unformed_module() must wait to return for any case other than MODULE_STATE_LIVE to prevent a race between multiple loads of dependent modules. Signed-off-by: Prarit Bhargava Signed-off-by: Barret Rhoden Cc: David Arcari Cc: Jessica Yu Cc: Heiko Carstens Signed-off-by: Jessica Yu