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Own branch of Oasis Linux (upstream: <https://git.sr.ht/~mcf/oasis/>) git clone https://anongit.hacktivis.me/git/oasis.git

0004-Fix-fread-error-checking.patch (2174B)

    

  1. From c3c72b271de395d0e4421e736700d60f96614725 Mon Sep 17 00:00:00 2001
  2. From: Michael Forney <mforney@mforney.org>
  3. Date: Sat, 1 May 2021 00:23:39 -0700
  4. Subject: [PATCH] Fix fread error checking
  6. fread returns size_t, an unsigned type, so the error check and
  7. TEMP_FAILURE_RETRY had no effect.
  9. Instead, errors can be detected when fread returns a partial amount
  10. and the ferror flag is set.
  11. ---
  12.  libnetlink.c | 27 ++++++++++++++-------------
  13.  1 file changed, 14 insertions(+), 13 deletions(-)
  15. diff --git a/libnetlink.c b/libnetlink.c
  16. index 24948bf..d94bd5f 100644
  17. --- a/libnetlink.c
  18. +++ b/libnetlink.c
  19. @@ -432,7 +432,7 @@ int rtnl_listen(struct rtnl_handle *rtnl,
  20.  int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
  21.  		   void *jarg)
  22.  {
  23. -	int status;
  24. +	size_t status;
  25.  	struct sockaddr_nl nladdr;
  26.  	char   buf[8192];
  27.  	struct nlmsghdr *h = (void*)buf;
  28. @@ -442,18 +442,19 @@ int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
  29.  	nladdr.nl_pid = 0;
  30.  	nladdr.nl_groups = 0;
  31.  
  32. -	while (1) {
  33. +	while (!feof(rtnl)) {
  34.  		int err, len;
  35.  		int l;
  36.  
  37. -		status = TEMP_FAILURE_RETRY ( fread(&buf, 1, sizeof(*h), rtnl) );
  38. +		status = fread(&buf, 1, sizeof(*h), rtnl);
  39.  
  40. -		if (status < 0) {
  41. -			perror("rtnl_from_file: fread");
  42. +		if (status < sizeof(*h)) {
  43. +			if (ferror(rtnl))
  44. +				perror("rtnl_from_file: fread");
  45. +			else
  46. +				fprintf(stderr, "rtnl_from_file: truncated message\n");
  47.  			return -1;
  48.  		}
  49. -		if (status == 0)
  50. -			return 0;
  51.  
  52.  		len = h->nlmsg_len;
  53.  		l = len - sizeof(*h);
  54. @@ -466,12 +467,11 @@ int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
  55.  
  56.  		status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
  57.  
  58. -		if (status < 0) {
  59. -			perror("rtnl_from_file: fread");
  60. -			return -1;
  61. -		}
  62. -		if (status < l) {
  63. -			fprintf(stderr, "rtnl-from_file: truncated message\n");
  64. +		if (status < NLMSG_ALIGN(l)) {
  65. +			if (ferror(rtnl))
  66. +				perror("rtnl_from_file: fread");
  67. +			else
  68. +				fprintf(stderr, "rtnl_from_file: truncated message\n");
  69.  			return -1;
  70.  		}
  71.  
  72. @@ -479,6 +479,7 @@ int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
  73.  		if (err < 0)
  74.  			return err;
  75.  	}
  76. +	return 0;
  77.  }
  78.  
  79.  int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
  80. -- 
  81. 2.37.3