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| author | Mikel Rychliski <mikel@mikelr.com> | 2024-09-30 16:26:54 -0400 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2024-10-23 17:24:44 +0900 |
| commit | 73f35080477e893aa6f4c8d388352b871b288fbc (patch) | |
| tree | 7700f13cec1bd8a133814862839e444f3d318538 /kernel/trace/trace_uprobe.c | |
| parent | objpool: fix choosing allocation for percpu slots (diff) | |
| download | linux-73f35080477e893aa6f4c8d388352b871b288fbc.tar.gz linux-73f35080477e893aa6f4c8d388352b871b288fbc.zip | |
tracing/probes: Fix MAX_TRACE_ARGS limit handling
When creating a trace_probe we would set nr_args prior to truncating the
arguments to MAX_TRACE_ARGS. However, we would only initialize arguments
up to the limit.
This caused invalid memory access when attempting to set up probes with
more than 128 fetchargs.
BUG: kernel NULL pointer dereference, address: 0000000000000020
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
RIP: 0010:__set_print_fmt+0x134/0x330
Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return
an error when there are too many arguments instead of silently
truncating.
Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/
Fixes: 035ba76014c0 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init")
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'kernel/trace/trace_uprobe.c')
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 13f9270ed5ab..b30fc8fcd095 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -565,6 +565,8 @@ static int __trace_uprobe_create(int argc, const char **argv) if (argc < 2) return -ECANCELED; + if (argc - 2 > MAX_TRACE_ARGS) + return -E2BIG; if (argv[0][1] == ':') event = &argv[0][2]; @@ -690,7 +692,7 @@ static int __trace_uprobe_create(int argc, const char **argv) tu->filename = filename; /* parse arguments */ - for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + for (i = 0; i < argc; i++) { struct traceprobe_parse_context ctx = { .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER, }; |