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5 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Suren Baghdasaryan
|
2c321f3f70 |
mm: change inlined allocation helpers to account at the call site
Main goal of memory allocation profiling patchset is to provide accounting that is cheap enough to run in production. To achieve that we inject counters using codetags at the allocation call sites to account every time allocation is made. This injection allows us to perform accounting efficiently because injected counters are immediately available as opposed to the alternative methods, such as using _RET_IP_, which would require counter lookup and appropriate locking that makes accounting much more expensive. This method requires all allocation functions to inject separate counters at their call sites so that their callers can be individually accounted. Counter injection is implemented by allocation hooks which should wrap all allocation functions. Inlined functions which perform allocations but do not use allocation hooks are directly charged for the allocations they perform. In most cases these functions are just specialized allocation wrappers used from multiple places to allocate objects of a specific type. It would be more useful to do the accounting at their call sites instead. Instrument these helpers to do accounting at the call site. Simple inlined allocation wrappers are converted directly into macros. More complex allocators or allocators with documentation are converted into _noprof versions and allocation hooks are added. This allows memory allocation profiling mechanism to charge allocations to the callers of these functions. Link: https://lkml.kernel.org/r/20240415020731.1152108-1-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Jan Kara <jack@suse.cz> [jbd2] Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jakub Sitnicki <jakub@cloudflare.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Jinghao Jia
|
e2dcac2f58 |
BPF: Fix potential bad pointer dereference in bpf_sys_bpf()
The bpf_sys_bpf() helper function allows an eBPF program to load another
eBPF program from within the kernel. In this case the argument union
bpf_attr pointer (as well as the insns and license pointers inside) is a
kernel address instead of a userspace address (which is the case of a
usual bpf() syscall). To make the memory copying process in the syscall
work in both cases, bpfptr_t was introduced to wrap around the pointer
and distinguish its origin. Specifically, when copying memory contents
from a bpfptr_t, a copy_from_user() is performed in case of a userspace
address and a memcpy() is performed for a kernel address.
This can lead to problems because the in-kernel pointer is never checked
for validity. The problem happens when an eBPF syscall program tries to
call bpf_sys_bpf() to load a program but provides a bad insns pointer --
say 0xdeadbeef -- in the bpf_attr union. The helper calls __sys_bpf()
which would then call bpf_prog_load() to load the program.
bpf_prog_load() is responsible for copying the eBPF instructions to the
newly allocated memory for the program; it creates a kernel bpfptr_t for
insns and invokes copy_from_bpfptr(). Internally, all bpfptr_t
operations are backed by the corresponding sockptr_t operations, which
performs direct memcpy() on kernel pointers for copy_from/strncpy_from
operations. Therefore, the code is always happy to dereference the bad
pointer to trigger a un-handle-able page fault and in turn an oops.
However, this is not supposed to happen because at that point the eBPF
program is already verified and should not cause a memory error.
Sample KASAN trace:
[ 25.685056][ T228] ==================================================================
[ 25.685680][ T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30
[ 25.686210][ T228] Read of size 80 at addr 00000000deadbeef by task poc/228
[ 25.686732][ T228]
[ 25.686893][ T228] CPU: 3 PID: 228 Comm: poc Not tainted 5.19.0-rc7 #7
[ 25.687375][ T228] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014
[ 25.687991][ T228] Call Trace:
[ 25.688223][ T228] <TASK>
[ 25.688429][ T228] dump_stack_lvl+0x73/0x9e
[ 25.688747][ T228] print_report+0xea/0x200
[ 25.689061][ T228] ? copy_from_bpfptr+0x21/0x30
[ 25.689401][ T228] ? _printk+0x54/0x6e
[ 25.689693][ T228] ? _raw_spin_lock_irqsave+0x70/0xd0
[ 25.690071][ T228] ? copy_from_bpfptr+0x21/0x30
[ 25.690412][ T228] kasan_report+0xb5/0xe0
[ 25.690716][ T228] ? copy_from_bpfptr+0x21/0x30
[ 25.691059][ T228] kasan_check_range+0x2bd/0x2e0
[ 25.691405][ T228] ? copy_from_bpfptr+0x21/0x30
[ 25.691734][ T228] memcpy+0x25/0x60
[ 25.692000][ T228] copy_from_bpfptr+0x21/0x30
[ 25.692328][ T228] bpf_prog_load+0x604/0x9e0
[ 25.692653][ T228] ? cap_capable+0xb4/0xe0
[ 25.692956][ T228] ? security_capable+0x4f/0x70
[ 25.693324][ T228] __sys_bpf+0x3af/0x580
[ 25.693635][ T228] bpf_sys_bpf+0x45/0x240
[ 25.693937][ T228] bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd
[ 25.694394][ T228] bpf_prog_run_pin_on_cpu+0x2f/0xb0
[ 25.694756][ T228] bpf_prog_test_run_syscall+0x146/0x1c0
[ 25.695144][ T228] bpf_prog_test_run+0x172/0x190
[ 25.695487][ T228] __sys_bpf+0x2c5/0x580
[ 25.695776][ T228] __x64_sys_bpf+0x3a/0x50
[ 25.696084][ T228] do_syscall_64+0x60/0x90
[ 25.696393][ T228] ? fpregs_assert_state_consistent+0x50/0x60
[ 25.696815][ T228] ? exit_to_user_mode_prepare+0x36/0xa0
[ 25.697202][ T228] ? syscall_exit_to_user_mode+0x20/0x40
[ 25.697586][ T228] ? do_syscall_64+0x6e/0x90
[ 25.697899][ T228] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 25.698312][ T228] RIP: 0033:0x7f6d543fb759
[ 25.698624][ T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 a6 0e 00 f7 d8 64 89 01 48
[ 25.699946][ T228] RSP: 002b:00007ffc3df78468 EFLAGS: 00000287 ORIG_RAX: 0000000000000141
[ 25.700526][ T228] RAX: ffffffffffffffda RBX: 00007ffc3df78628 RCX: 00007f6d543fb759
[ 25.701071][ T228] RDX: 0000000000000090 RSI: 00007ffc3df78478 RDI: 000000000000000a
[ 25.701636][ T228] RBP: 00007ffc3df78510 R08: 0000000000000000 R09: 0000000000300000
[ 25.702191][ T228] R10: 0000000000000005 R11: 0000000000000287 R12: 0000000000000000
[ 25.702736][ T228] R13: 00007ffc3df78638 R14: 000055a1584aca68 R15: 00007f6d5456a000
[ 25.703282][ T228] </TASK>
[ 25.703490][ T228] ==================================================================
[ 25.704050][ T228] Disabling lock debugging due to kernel taint
Update copy_from_bpfptr() and strncpy_from_bpfptr() so that:
- for a kernel pointer, it uses the safe copy_from_kernel_nofault() and
strncpy_from_kernel_nofault() functions.
- for a userspace pointer, it performs copy_from_user() and
strncpy_from_user().
Fixes:
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Kumar Kartikeya Dwivedi
|
14f267d95f |
bpf: btf: Introduce helpers for dynamic BTF set registration
This adds helpers for registering btf_id_set from modules and the bpf_check_mod_kfunc_call callback that can be used to look them up. With in kernel sets, the way this is supposed to work is, in kernel callback looks up within the in-kernel kfunc whitelist, and then defers to the dynamic BTF set lookup if it doesn't find the BTF id. If there is no in-kernel BTF id set, this callback can be used directly. Also fix includes for btf.h and bpfptr.h so that they can included in isolation. This is in preparation for their usage in tcp_bbr, tcp_cubic and tcp_dctcp modules in the next patch. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211002011757.311265-4-memxor@gmail.com |
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Stanislav Fomichev
|
44779a4b85 |
bpf: Use kvmalloc for map keys in syscalls
Same as previous patch but for the keys. memdup_bpfptr is renamed to kvmemdup_bpfptr (and converted to kvmalloc). Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210818235216.1159202-2-sdf@google.com |
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Alexei Starovoitov
|
cdf7fb0a9f |
bpf: Introduce bpfptr_t user/kernel pointer.
Similar to sockptr_t introduce bpfptr_t with few additions: make_bpfptr() creates new user/kernel pointer in the same address space as existing user/kernel pointer. bpfptr_add() advances the user/kernel pointer. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-3-alexei.starovoitov@gmail.com |