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authorYang Yingliang <yangyingliang@huawei.com>2019-06-20 10:18:14 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-19 09:09:40 +0200
commitae415d7a27071d807cfdd04c27dc02cce43c10c3 (patch)
tree2f6d1096d61a14a64ed8373e581ef121b4a18d8f /kernel
parent0ae0c43abcbfa957219e4d3c6e808459c0e681b7 (diff)
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modules: fix BUG when load module with rodata=n
commit 2eef1399a866c57687962e15142b141a4f8e7862 upstream. 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 <cj.chengjian@huawei.com> Reviewed-by: Nadav Amit <namit@vmware.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 0d86fc73d63d..1dbf8113a5c2 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1956,13 +1956,9 @@ void module_enable_ro(const struct module *mod, bool after_init)
return;
frob_text(&mod->core_layout, set_memory_ro);
- frob_text(&mod->core_layout, set_memory_x);
frob_rodata(&mod->core_layout, set_memory_ro);
-
frob_text(&mod->init_layout, set_memory_ro);
- frob_text(&mod->init_layout, set_memory_x);
-
frob_rodata(&mod->init_layout, set_memory_ro);
if (after_init)
@@ -2049,6 +2045,12 @@ static void module_enable_nx(const struct module *mod) { }
static void module_disable_nx(const struct module *mod) { }
#endif
+static void module_enable_x(const struct module *mod)
+{
+ frob_text(&mod->core_layout, set_memory_x);
+ frob_text(&mod->init_layout, set_memory_x);
+}
+
#ifdef CONFIG_LIVEPATCH
/*
* Persist Elf information about a module. Copy the Elf header,
@@ -3604,6 +3606,7 @@ static int complete_formation(struct module *mod, struct load_info *info)
module_enable_ro(mod, false);
module_enable_nx(mod);
+ module_enable_x(mod);
/* Mark state as coming so strong_try_module_get() ignores us,
* but kallsyms etc. can see us. */