From 46dad3c1e57897ab9228332f03e1c14798d2d3b9 Mon Sep 17 00:00:00 2001 From: Yuntao Wang Date: Fri, 12 Apr 2024 16:17:32 +0800 Subject: init/main.c: Fix potential static_command_line memory overflow We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for static_command_line, but the strings copied into static_command_line are extra_command_line and command_line, rather than extra_command_line and boot_command_line. When strlen(command_line) > strlen(boot_command_line), static_command_line will overflow. This patch just recovers strlen(command_line) which was miss-consolidated with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()") Link: https://lore.kernel.org/all/20240412081733.35925-2-ytcoode@gmail.com/ Fixes: f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()") Cc: stable@vger.kernel.org Signed-off-by: Yuntao Wang Signed-off-by: Masami Hiramatsu (Google) --- init/main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/init/main.c b/init/main.c index 881f6230ee59e9..5dcf5274c09c7a 100644 --- a/init/main.c +++ b/init/main.c @@ -636,6 +636,8 @@ static void __init setup_command_line(char *command_line) if (!saved_command_line) panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); + len = xlen + strlen(command_line) + 1; + static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); if (!static_command_line) panic("%s: Failed to allocate %zu bytes\n", __func__, len); -- cgit 1.2.3-korg From 89f9a1e876b5a7ad884918c03a46831af202c8a0 Mon Sep 17 00:00:00 2001 From: Qiang Zhang Date: Sun, 14 Apr 2024 19:49:45 +0800 Subject: bootconfig: use memblock_free_late to free xbc memory to buddy On the time to free xbc memory in xbc_exit(), memblock may has handed over memory to buddy allocator. So it doesn't make sense to free memory back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. Following KASAN logs shows this case. This patch fixes the xbc memory free problem by calling memblock_free() in early xbc init error rewind path and calling memblock_free_late() in xbc exit path to free memory to buddy allocator. [ 9.410890] ================================================================== [ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260 [ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1 [ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5 [ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023 [ 9.460789] Call Trace: [ 9.463518] [ 9.465859] dump_stack_lvl+0x53/0x70 [ 9.469949] print_report+0xce/0x610 [ 9.473944] ? __virt_addr_valid+0xf5/0x1b0 [ 9.478619] ? memblock_isolate_range+0x12d/0x260 [ 9.483877] kasan_report+0xc6/0x100 [ 9.487870] ? memblock_isolate_range+0x12d/0x260 [ 9.493125] memblock_isolate_range+0x12d/0x260 [ 9.498187] memblock_phys_free+0xb4/0x160 [ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10 [ 9.508021] ? mutex_unlock+0x7e/0xd0 [ 9.512111] ? __pfx_mutex_unlock+0x10/0x10 [ 9.516786] ? kernel_init_freeable+0x2d4/0x430 [ 9.521850] ? __pfx_kernel_init+0x10/0x10 [ 9.526426] xbc_exit+0x17/0x70 [ 9.529935] kernel_init+0x38/0x1e0 [ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30 [ 9.538601] ret_from_fork+0x2c/0x50 [ 9.542596] ? __pfx_kernel_init+0x10/0x10 [ 9.547170] ret_from_fork_asm+0x1a/0x30 [ 9.551552] [ 9.555649] The buggy address belongs to the physical page: [ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30 [ 9.570821] flags: 0x200000000000000(node=0|zone=2) [ 9.576271] page_type: 0xffffffff() [ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000 [ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 [ 9.597476] page dumped because: kasan: bad access detected [ 9.605362] Memory state around the buggy address: [ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.634930] ^ [ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.654675] ================================================================== Link: https://lore.kernel.org/all/20240414114944.1012359-1-qiang4.zhang@linux.intel.com/ Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed") Cc: Stable@vger.kernel.org Signed-off-by: Qiang Zhang Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- include/linux/bootconfig.h | 7 ++++++- lib/bootconfig.c | 19 +++++++++++-------- 2 files changed, 17 insertions(+), 9 deletions(-) diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h index e5ee2c694401e0..3f4b4ac527ca28 100644 --- a/include/linux/bootconfig.h +++ b/include/linux/bootconfig.h @@ -288,7 +288,12 @@ int __init xbc_init(const char *buf, size_t size, const char **emsg, int *epos); int __init xbc_get_info(int *node_size, size_t *data_size); /* XBC cleanup data structures */ -void __init xbc_exit(void); +void __init _xbc_exit(bool early); + +static inline void xbc_exit(void) +{ + _xbc_exit(false); +} /* XBC embedded bootconfig data in kernel */ #ifdef CONFIG_BOOT_CONFIG_EMBED diff --git a/lib/bootconfig.c b/lib/bootconfig.c index c59d26068a6401..8841554432d5b4 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -61,9 +61,12 @@ static inline void * __init xbc_alloc_mem(size_t size) return memblock_alloc(size, SMP_CACHE_BYTES); } -static inline void __init xbc_free_mem(void *addr, size_t size) +static inline void __init xbc_free_mem(void *addr, size_t size, bool early) { - memblock_free(addr, size); + if (early) + memblock_free(addr, size); + else if (addr) + memblock_free_late(__pa(addr), size); } #else /* !__KERNEL__ */ @@ -73,7 +76,7 @@ static inline void *xbc_alloc_mem(size_t size) return malloc(size); } -static inline void xbc_free_mem(void *addr, size_t size) +static inline void xbc_free_mem(void *addr, size_t size, bool early) { free(addr); } @@ -904,13 +907,13 @@ static int __init xbc_parse_tree(void) * If you need to reuse xbc_init() with new boot config, you can * use this. */ -void __init xbc_exit(void) +void __init _xbc_exit(bool early) { - xbc_free_mem(xbc_data, xbc_data_size); + xbc_free_mem(xbc_data, xbc_data_size, early); xbc_data = NULL; xbc_data_size = 0; xbc_node_num = 0; - xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX); + xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX, early); xbc_nodes = NULL; brace_index = 0; } @@ -963,7 +966,7 @@ int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos) if (!xbc_nodes) { if (emsg) *emsg = "Failed to allocate bootconfig nodes"; - xbc_exit(); + _xbc_exit(true); return -ENOMEM; } memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX); @@ -977,7 +980,7 @@ int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos) *epos = xbc_err_pos; if (emsg) *emsg = xbc_err_msg; - xbc_exit(); + _xbc_exit(true); } else ret = xbc_node_num; -- cgit 1.2.3-korg From 298b871cd55a607037ac8af0011b9fdeb54c1e65 Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Tue, 16 Apr 2024 06:44:04 +0900 Subject: bootconfig: Fix the kerneldoc of _xbc_exit() Fix the kerneldoc of _xbc_exit() which is updated to have an @early argument and the function name is changed. Link: https://lore.kernel.org/all/171321744474.599864.13532445969528690358.stgit@devnote2/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202404150036.kPJ3HEFA-lkp@intel.com/ Fixes: 89f9a1e876b5 ("bootconfig: use memblock_free_late to free xbc memory to buddy") Signed-off-by: Masami Hiramatsu (Google) --- lib/bootconfig.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/bootconfig.c b/lib/bootconfig.c index 8841554432d5b4..97f8911ea339e6 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -901,7 +901,8 @@ static int __init xbc_parse_tree(void) } /** - * xbc_exit() - Clean up all parsed bootconfig + * _xbc_exit() - Clean up all parsed bootconfig + * @early: Set true if this is called before budy system is initialized. * * This clears all data structures of parsed bootconfig on memory. * If you need to reuse xbc_init() with new boot config, you can -- cgit 1.2.3-korg