a676308085
Fix the following kasan issue reported by syzbot: BUG: KASAN: slab-out-of-bounds in __skb_frag_set_page include/linux/skbuff.h:3242 [inline] BUG: KASAN: slab-out-of-bounds in bpf_prog_test_run_xdp+0x10ac/0x1150 net/bpf/test_run.c:972 Write of size 8 at addr ffff888048c75000 by task syz-executor.5/23405 CPU: 1 PID: 23405 Comm: syz-executor.5 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 __skb_frag_set_page include/linux/skbuff.h:3242 [inline] bpf_prog_test_run_xdp+0x10ac/0x1150 net/bpf/test_run.c:972 bpf_prog_test_run kernel/bpf/syscall.c:3356 [inline] __sys_bpf+0x1858/0x59a0 kernel/bpf/syscall.c:4658 __do_sys_bpf kernel/bpf/syscall.c:4744 [inline] __se_sys_bpf kernel/bpf/syscall.c:4742 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4742 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4ea30dd059 RSP: 002b:00007f4ea1a52168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f4ea31eff60 RCX: 00007f4ea30dd059 RDX: 0000000000000048 RSI: 0000000020000000 RDI: 000000000000000a RBP: 00007f4ea313708d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc8367c5af R14: 00007f4ea1a52300 R15: 0000000000022000 </TASK> Allocated by task 23405: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:586 [inline] kzalloc include/linux/slab.h:715 [inline] bpf_test_init.isra.0+0x9f/0x150 net/bpf/test_run.c:411 bpf_prog_test_run_xdp+0x2f8/0x1150 net/bpf/test_run.c:941 bpf_prog_test_run kernel/bpf/syscall.c:3356 [inline] __sys_bpf+0x1858/0x59a0 kernel/bpf/syscall.c:4658 __do_sys_bpf kernel/bpf/syscall.c:4744 [inline] __se_sys_bpf kernel/bpf/syscall.c:4742 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4742 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888048c74000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes to the right of 4096-byte region [ffff888048c74000, ffff888048c75000) The buggy address belongs to the page: page:ffffea0001231c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x48c70 head:ffffea0001231c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c42140 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0x28a/0x3b0 mm/slub.c:2004 ___slab_alloc+0x87c/0xe90 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] __kmalloc_node_track_caller+0x2cb/0x360 mm/slub.c:4957 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1159 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:745 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:802 [inline] nsim_dev_trap_report_work+0x29a/0xbc0 drivers/net/netdevsim/dev.c:843 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6d/0x160 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3243 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags include/linux/audit.h:323 [inline] getname+0x8e/0xd0 fs/namei.c:217 do_sys_openat2+0xf5/0x4d0 fs/open.c:1208 do_sys_open fs/open.c:1230 [inline] __do_sys_openat fs/open.c:1246 [inline] __se_sys_openat fs/open.c:1241 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1241 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888048c74f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888048c74f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888048c75080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888048c75100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Fixes: 1c19499825246 ("bpf: introduce frags support to bpf_prog_test_run_xdp()") Reported-by: syzbot+6d70ca7438345077c549@syzkaller.appspotmail.com Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/688c26f9dd6e885e58e8e834ede3f0139bb7fa95.1643835097.git.lorenzo@kernel.org
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.