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Filename Latest commit message Latest commit date
Steven Rostedt (Google) 60e092289c tracing: Inform kmemleak of saved_cmdlines allocation
commit 2394ac4145ea91b92271e675a09af2a9ea6840b7 upstream.

The allocation of the struct saved_cmdlines_buffer structure changed from:

        s = kmalloc(sizeof(*s), GFP_KERNEL);
	s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);

to:

	orig_size = sizeof(*s) + val * TASK_COMM_LEN;
	order = get_order(orig_size);
	size = 1 << (order + PAGE_SHIFT);
	page = alloc_pages(GFP_KERNEL, order);
	if (!page)
		return NULL;

	s = page_address(page);
	memset(s, 0, sizeof(*s));

	s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);

Where that s->saved_cmdlines allocation looks to be a dangling allocation
to kmemleak. That's because kmemleak only keeps track of kmalloc()
allocations. For allocations that use page_alloc() directly, the kmemleak
needs to be explicitly informed about it.

Add kmemleak_alloc() and kmemleak_free() around the page allocation so
that it doesn't give the following false positive:

unreferenced object 0xffff8881010c8000 (size 32760):
  comm "swapper", pid 0, jiffies 4294667296
  hex dump (first 32 bytes):
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
  backtrace (crc ae6ec1b9):
    [<ffffffff86722405>] kmemleak_alloc+0x45/0x80
    [<ffffffff8414028d>] __kmalloc_large_node+0x10d/0x190
    [<ffffffff84146ab1>] __kmalloc+0x3b1/0x4c0
    [<ffffffff83ed7103>] allocate_cmdlines_buffer+0x113/0x230
    [<ffffffff88649c34>] tracer_alloc_buffers.isra.0+0x124/0x460
    [<ffffffff8864a174>] early_trace_init+0x14/0xa0
    [<ffffffff885dd5ae>] start_kernel+0x12e/0x3c0
    [<ffffffff885f5758>] x86_64_start_reservations+0x18/0x30
    [<ffffffff885f582b>] x86_64_start_kernel+0x7b/0x80
    [<ffffffff83a001c3>] secondary_startup_64_no_verify+0x15e/0x16b

Link: https://lore.kernel.org/linux-trace-kernel/87r0hfnr9r.fsf@kernel.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240214112046.09a322d6@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 44dc5c41b5b1 ("tracing: Fix wasted memory in saved_cmdlines logic")
Reported-by: Kalle Valo <kvalo@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 08:25:13 +01:00
arch x86/mm/ident_map: Use gbpages only where full GB page should be mapped. 2024-02-23 08:25:12 +01:00
block blk-mq: fix IO hang from sbitmap wakeup race 2024-02-23 08:25:03 +01:00
certs
crypto crypto: api - Disallow identical driver names 2024-02-23 08:24:48 +01:00
Documentation net: sysfs: Fix /sys/class/net/<iface> path 2024-02-23 08:25:05 +01:00
drivers pmdomain: core: Move the unused cleanup to a _sync initcall 2024-02-23 08:25:13 +01:00
fs nilfs2: fix hang in nilfs_lookup_dirty_data_buffers() 2024-02-23 08:25:12 +01:00
include hrtimer: Report offline hrtimer enqueue 2024-02-23 08:25:08 +01:00
init rootfs: Fix support for rootfstype= when root= is given 2024-01-25 14:34:30 -08:00
ipc
kernel tracing: Inform kmemleak of saved_cmdlines allocation 2024-02-23 08:25:13 +01:00
lib ida: Fix crash in ida_free when the bitmap is empty 2024-01-25 14:34:21 -08:00
LICENSES
mm mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again 2024-02-23 08:25:10 +01:00
net can: j1939: Fix UAF in j1939_sk_match_filter during setsockopt(SO_J1939_FILTER) 2024-02-23 08:25:13 +01:00
samples samples/bpf: Fix buffer overflow in tcp_basertt 2023-07-27 08:37:07 +02:00
scripts kbuild: Fix changing ELF file type for output of gen_btf for big endian 2024-02-23 08:25:10 +01:00
security apparmor: avoid crash when parsed profile name is empty 2024-01-25 14:34:31 -08:00
sound ALSA: hda/conexant: Add quirk for SWS JS201D 2024-02-23 08:25:12 +01:00
tools selftests: net: avoid just another constant wait 2024-02-23 08:25:06 +01:00
usr
virt KVM: Destroy target device if coalesced MMIO unregistration fails 2023-03-11 16:44:01 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-30 16:27:12 +02:00
Makefile Linux 5.4.268 2024-01-25 14:34:33 -08:00
README

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.