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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-19 22:50:48 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-19 22:50:48 +0100 |
commit | e4365e369fcc974057377e8cdcd9dfe5a7b05b62 (patch) | |
tree | 3ee667ce689f74de3a712fbc6c5109c4b2bbef45 /kernel | |
parent | Merge tag 'perf-tools-fixes-for-v5.16-2021-11-19' of git://git.kernel.org/pub... (diff) | |
parent | tracing: Don't use out-of-sync va_list in event printing (diff) | |
download | linux-e4365e369fcc974057377e8cdcd9dfe5a7b05b62.tar.xz linux-e4365e369fcc974057377e8cdcd9dfe5a7b05b62.zip |
Merge tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix double free in destroy_hist_field
- Harden memset() of trace_iterator structure
- Do not warn in trace printk check when test buffer fills up
* tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Don't use out-of-sync va_list in event printing
tracing: Use memset_startat() to zero struct trace_iterator
tracing/histogram: Fix UAF in destroy_hist_field()
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/trace/trace.c | 16 | ||||
-rw-r--r-- | kernel/trace/trace_events_hist.c | 41 |
2 files changed, 35 insertions, 22 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f9139dc1262c..88de94da596b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3812,6 +3812,18 @@ void trace_check_vprintf(struct trace_iterator *iter, const char *fmt, iter->fmt[i] = '\0'; trace_seq_vprintf(&iter->seq, iter->fmt, ap); + /* + * If iter->seq is full, the above call no longer guarantees + * that ap is in sync with fmt processing, and further calls + * to va_arg() can return wrong positional arguments. + * + * Ensure that ap is no longer used in this case. + */ + if (iter->seq.full) { + p = ""; + break; + } + if (star) len = va_arg(ap, int); @@ -6706,9 +6718,7 @@ waitagain: cnt = PAGE_SIZE - 1; /* reset all but tr, trace, and overruns */ - memset(&iter->seq, 0, - sizeof(struct trace_iterator) - - offsetof(struct trace_iterator, seq)); + memset_startat(iter, 0, seq); cpumask_clear(iter->started); trace_seq_init(&iter->seq); iter->pos = -1; diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 5ea2c9ec54a6..9555b8e1d1e3 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2576,28 +2576,27 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, /* Split the expression string at the root operator */ if (!sep) - goto free; + return ERR_PTR(-EINVAL); + *sep = '\0'; operand1_str = str; str = sep+1; /* Binary operator requires both operands */ if (*operand1_str == '\0' || *str == '\0') - goto free; + return ERR_PTR(-EINVAL); operand_flags = 0; /* LHS of string is an expression e.g. a+b in a+b+c */ operand1 = parse_expr(hist_data, file, operand1_str, operand_flags, NULL, n_subexprs); - if (IS_ERR(operand1)) { - ret = PTR_ERR(operand1); - operand1 = NULL; - goto free; - } + if (IS_ERR(operand1)) + return ERR_CAST(operand1); + if (operand1->flags & HIST_FIELD_FL_STRING) { hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str)); ret = -EINVAL; - goto free; + goto free_op1; } /* RHS of string is another expression e.g. c in a+b+c */ @@ -2605,13 +2604,12 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, n_subexprs); if (IS_ERR(operand2)) { ret = PTR_ERR(operand2); - operand2 = NULL; - goto free; + goto free_op1; } if (operand2->flags & HIST_FIELD_FL_STRING) { hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); ret = -EINVAL; - goto free; + goto free_operands; } switch (field_op) { @@ -2629,12 +2627,12 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, break; default: ret = -EINVAL; - goto free; + goto free_operands; } ret = check_expr_operands(file->tr, operand1, operand2, &var1, &var2); if (ret) - goto free; + goto free_operands; operand_flags = var1 ? var1->flags : operand1->flags; operand2_flags = var2 ? var2->flags : operand2->flags; @@ -2653,12 +2651,13 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, expr = create_hist_field(hist_data, NULL, flags, var_name); if (!expr) { ret = -ENOMEM; - goto free; + goto free_operands; } operand1->read_once = true; operand2->read_once = true; + /* The operands are now owned and free'd by 'expr' */ expr->operands[0] = operand1; expr->operands[1] = operand2; @@ -2669,7 +2668,7 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, if (!divisor) { hist_err(file->tr, HIST_ERR_DIVISION_BY_ZERO, errpos(str)); ret = -EDOM; - goto free; + goto free_expr; } /* @@ -2709,18 +2708,22 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, expr->type = kstrdup_const(operand1->type, GFP_KERNEL); if (!expr->type) { ret = -ENOMEM; - goto free; + goto free_expr; } expr->name = expr_str(expr, 0); } return expr; -free: - destroy_hist_field(operand1, 0); + +free_operands: destroy_hist_field(operand2, 0); - destroy_hist_field(expr, 0); +free_op1: + destroy_hist_field(operand1, 0); + return ERR_PTR(ret); +free_expr: + destroy_hist_field(expr, 0); return ERR_PTR(ret); } |