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2023-12-29kasan: simplify kasan_complete_mode_report_info for tag-based modesAndrey Konovalov1-19/+4
memcpy the alloc/free tracks when collecting the information about a bad access instead of copying fields one by one. Link: https://lkml.kernel.org/r/20231221183540.168428-4-andrey.konovalov@linux.dev Fixes: 5d4c6ac94694 ("kasan: record and report more information") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Juntong Deng <juntong.deng@outlook.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: reuse kasan_track in kasan_stack_ring_entryAndrey Konovalov1-6/+6
Avoid duplicating fields of kasan_track in kasan_stack_ring_entry: reuse the structure. Link: https://lkml.kernel.org/r/20231221183540.168428-2-andrey.konovalov@linux.dev Fixes: 5d4c6ac94694 ("kasan: record and report more information") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Juntong Deng <juntong.deng@outlook.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-11kasan: record and report more informationJuntong Deng1-0/+15
Record and report more information to help us find the cause of the bug and to help us correlate the error with other system events. This patch adds recording and showing CPU number and timestamp at allocation and free (controlled by CONFIG_KASAN_EXTRA_INFO). The timestamps in the report use the same format and source as printk. Error occurrence timestamp is already implicit in the printk log, and CPU number is already shown by dump_stack_lvl, so there is no need to add it. In order to record CPU number and timestamp at allocation and free, corresponding members need to be added to the relevant data structures, which will lead to increased memory consumption. In Generic KASAN, members are added to struct kasan_track. Since in most cases, alloc meta is stored in the redzone and free meta is stored in the object or the redzone, memory consumption will not increase much. In SW_TAGS KASAN and HW_TAGS KASAN, members are added to struct kasan_stack_ring_entry. Memory consumption increases as the size of struct kasan_stack_ring_entry increases (this part of the memory is allocated by memblock), but since this is configurable, it is up to the user to choose. Link: https://lkml.kernel.org/r/VI1P193MB0752BD991325D10E4AB1913599BDA@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM Signed-off-by: Juntong Deng <juntong.deng@outlook.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-11kasan: check object_size in kasan_complete_mode_report_infoAndrey Konovalov1-1/+3
Check the object size when looking up entries in the stack ring. If the size of the object for which a report is being printed does not match the size of the object for which a stack trace has been saved in the stack ring, the saved stack trace is irrelevant. Link: https://lkml.kernel.org/r/68c6948175aadd7e7e7deea61725103d64a4528f.1700502145.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-11kasan: remove atomic accesses to stack ring entriesAndrey Konovalov1-18/+7
Remove the atomic accesses to entry fields in save_stack_info and kasan_complete_mode_report_info for tag-based KASAN modes. These atomics are not required, as the read/write lock prevents the entries from being read (in kasan_complete_mode_report_info) while being written (in save_stack_info) and the try_cmpxchg prevents the same entry from being rewritten (in save_stack_info) in the unlikely case of wrapping during writing. Link: https://lkml.kernel.org/r/29f59126d9845c5257b6c29cd7ad113b16f19f47.1700502145.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-10kasan: infer allocation size by scanning metadataKuan-Ying Lee1-1/+1
Make KASAN scan metadata to infer the requested allocation size instead of printing cache->object_size. This patch fixes confusing slab-out-of-bounds reports as reported in: https://bugzilla.kernel.org/show_bug.cgi?id=216457 As an example of the confusing behavior, the report below hints that the allocation size was 192, while the kernel actually called kmalloc(184): ================================================================== BUG: KASAN: slab-out-of-bounds in _find_next_bit+0x143/0x160 lib/find_bit.c:109 Read of size 8 at addr ffff8880175766b8 by task kworker/1:1/26 ... The buggy address belongs to the object at ffff888017576600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 184 bytes inside of 192-byte region [ffff888017576600, ffff8880175766c0) ... Memory state around the buggy address: ffff888017576580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888017576600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888017576680: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ^ ffff888017576700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888017576780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== With this patch, the report shows: ================================================================== ... The buggy address belongs to the object at ffff888017576600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 0 bytes to the right of allocated 184-byte region [ffff888017576600, ffff8880175766b8) ... ================================================================== Also report slab use-after-free bugs as "slab-use-after-free" and print "freed" instead of "allocated" in the report when describing the accessed memory region. Also improve the metadata-related comment in kasan_find_first_bad_addr and use addr_has_metadata across KASAN code instead of open-coding KASAN_SHADOW_START checks. [akpm@linux-foundation.org: fix printk warning] Link: https://bugzilla.kernel.org/show_bug.cgi?id=216457 Link: https://lkml.kernel.org/r/20230129021437.18812-1-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Co-developed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: better invalid/double-free report headerAndrey Konovalov1-1/+1
Update the report header for invalid- and double-free bugs to contain the address being freed: BUG: KASAN: invalid-free in kfree+0x280/0x2a8 Free of addr ffff00000beac001 by task kunit_try_catch/99 Link: https://lkml.kernel.org/r/fce40f8dbd160972fe01a1ff39d0c426c310e4b7.1662852281.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: better identify bug types for tag-based modesAndrey Konovalov1-4/+21
Identify the bug type for the tag-based modes based on the stack trace entries found in the stack ring. If a free entry is found first (meaning that it was added last), mark the bug as use-after-free. If an alloc entry is found first, mark the bug as slab-out-of-bounds. Otherwise, assign the common bug type. This change returns the functionalify of the previously dropped CONFIG_KASAN_TAGS_IDENTIFY. Link: https://lkml.kernel.org/r/13ce7fa07d9d995caedd1439dfae4d51401842f2.1662411800.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: dynamically allocate stack ring entriesAndrey Konovalov1-2/+2
Instead of using a large static array, allocate the stack ring dynamically via memblock_alloc(). The size of the stack ring is controlled by a new kasan.stack_ring_size command-line parameter. When kasan.stack_ring_size is not provided, the default value of 32 << 10 is used. When the stack trace collection is disabled via kasan.stacktrace=off, the stack ring is not allocated. Link: https://lkml.kernel.org/r/03b82ab60db53427e9818e0b0c1971baa10c3cbc.1662411800.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: implement stack ring for tag-based modesAndrey Konovalov1-0/+71
Implement storing stack depot handles for alloc/free stack traces for slab objects for the tag-based KASAN modes in a ring buffer. This ring buffer is referred to as the stack ring. On each alloc/free of a slab object, the tagged address of the object and the current stack trace are recorded in the stack ring. On each bug report, if the accessed address belongs to a slab object, the stack ring is scanned for matching entries. The newest entries are used to print the alloc/free stack traces in the report: one entry for alloc and one for free. The number of entries in the stack ring is fixed in this patch, but one of the following patches adds a command-line argument to control it. [andreyknvl@google.com: initialize read-write lock in stack ring] Link: https://lkml.kernel.org/r/576182d194e27531e8090bad809e4136953895f4.1663700262.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/692de14b6b6a1bc817fd55e4ad92fc1f83c1ab59.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: introduce kasan_complete_mode_report_infoAndrey Konovalov1-10/+3
Add bug_type and alloc/free_track fields to kasan_report_info and add a kasan_complete_mode_report_info() function that fills in these fields. This function is implemented differently for different KASAN mode. Change the reporting code to use the filled in fields instead of invoking kasan_get_bug_type() and kasan_get_alloc/free_track(). For the Generic mode, kasan_complete_mode_report_info() invokes these functions instead. For the tag-based modes, only the bug_type field is filled in; alloc/free_track are handled in the next patch. Using a single function that fills in these fields is required for the tag-based modes, as the values for all three fields are determined in a single procedure implemented in the following patch. Link: https://lkml.kernel.org/r/8432b861054fa8d0cee79a8877dedeaf3b677ca8.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: move kasan_get_alloc/free_track definitionsAndrey Konovalov1-0/+12
Move the definitions of kasan_get_alloc/free_track() to report_*.c, as they belong with other the reporting code. Link: https://lkml.kernel.org/r/0cb15423956889b3905a0174b58782633bbbd72e.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-04kasan: drop CONFIG_KASAN_TAGS_IDENTIFYAndrey Konovalov1-28/+0
Drop CONFIG_KASAN_TAGS_IDENTIFY and related code to simplify making changes to the reporting code. The dropped functionality will be restored in the following patches in this series. Link: https://lkml.kernel.org/r/4c66ba98eb237e9ed9312c19d423bbcf4ecf88f8.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-03-25kasan: rename kasan_access_info to kasan_report_infoAndrey Konovalov1-1/+1
Rename kasan_access_info to kasan_report_info, as the latter name better reflects the struct's purpose. Link: https://lkml.kernel.org/r/158a4219a5d356901d017352558c989533a0782c.1646237226.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-06mm/kasan: Convert to struct folio and struct slabMatthew Wilcox (Oracle)1-5/+5
KASAN accesses some slab related struct page fields so we need to convert it to struct slab. Some places are a bit simplified thanks to kasan_addr_to_slab() encapsulating the PageSlab flag check through virt_to_slab(). When resolving object address to either a real slab or a large kmalloc, use struct folio as the intermediate type for testing the slab flag to avoid unnecessary implicit compound_head(). [ vbabka@suse.cz: use struct folio, adjust to differences in previous patches ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Tested-by: Hyeongogn Yoo <42.hyeyoo@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <kasan-dev@googlegroups.com>
2022-01-06mm: Convert struct page to struct slab in functions used by other subsystemsVlastimil Babka1-1/+1
KASAN, KFENCE and memcg interact with SLAB or SLUB internals through functions nearest_obj(), obj_to_index() and objs_per_slab() that use struct page as parameter. This patch converts it to struct slab including all callers, through a coccinelle semantic patch. // Options: --include-headers --no-includes --smpl-spacing include/linux/slab_def.h include/linux/slub_def.h mm/slab.h mm/kasan/*.c mm/kfence/kfence_test.c mm/memcontrol.c mm/slab.c mm/slub.c // Note: needs coccinelle 1.1.1 to avoid breaking whitespace @@ @@ -objs_per_slab_page( +objs_per_slab( ... ) { ... } @@ @@ -objs_per_slab_page( +objs_per_slab( ... ) @@ identifier fn =~ "obj_to_index|objs_per_slab"; @@ fn(..., - const struct page *page + const struct slab *slab ,...) { <... ( - page_address(page) + slab_address(slab) | - page + slab ) ...> } @@ identifier fn =~ "nearest_obj"; @@ fn(..., - struct page *page + const struct slab *slab ,...) { <... ( - page_address(page) + slab_address(slab) | - page + slab ) ...> } @@ identifier fn =~ "nearest_obj|obj_to_index|objs_per_slab"; expression E; @@ fn(..., ( - slab_page(E) + E | - virt_to_page(E) + virt_to_slab(E) | - virt_to_head_page(E) + virt_to_slab(E) | - page + page_slab(page) ) ,...) Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <kasan-dev@googlegroups.com> Cc: <cgroups@vger.kernel.org>
2021-06-29kasan: integrate the common part of two KASAN tag-based modesKuan-Ying Lee1-0/+51
1. Move kasan_get_free_track() and kasan_set_free_info() into tags.c and combine these two functions for SW_TAGS and HW_TAGS kasan mode. 2. Move kasan_get_bug_type() to report_tags.c and make this function compatible for SW_TAGS and HW_TAGS kasan mode. Link: https://lkml.kernel.org/r/20210626100931.22794-3-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Suggested-by: Marco Elver <elver@google.com> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Nicholas Tang <nicholas.tang@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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