* [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR'
@ 2024-08-13 8:00 Dan Carpenter
2024-08-13 18:16 ` Al Viro
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2024-08-13 8:00 UTC (permalink / raw)
To: oe-kbuild, Al Viro; +Cc: lkp, oe-kbuild-all, linux-fsdevel
tree: https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git work.fdtable
head: 3f4b0acefd818ec43b68455994ac2bd5166c06ae
commit: 3f4b0acefd818ec43b68455994ac2bd5166c06ae [13/13] dup_fd(): change calling conventions
config: x86_64-randconfig-161-20240813 (https://download.01.org/0day-ci/archive/20240813/202408130945.I8wIAYBm-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202408130945.I8wIAYBm-lkp@intel.com/
smatch warnings:
kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR'
vim +/PTR_ERR +3242 kernel/fork.c
60997c3d45d9a6 Christian Brauner 2020-06-03 3232 int unshare_fd(unsigned long unshare_flags, unsigned int max_fds,
60997c3d45d9a6 Christian Brauner 2020-06-03 3233 struct files_struct **new_fdp)
cf2e340f4249b7 JANAK DESAI 2006-02-07 3234 {
cf2e340f4249b7 JANAK DESAI 2006-02-07 3235 struct files_struct *fd = current->files;
cf2e340f4249b7 JANAK DESAI 2006-02-07 3236
cf2e340f4249b7 JANAK DESAI 2006-02-07 3237 if ((unshare_flags & CLONE_FILES) &&
a016f3389c0660 JANAK DESAI 2006-02-07 3238 (fd && atomic_read(&fd->count) > 1)) {
3f4b0acefd818e Al Viro 2024-08-06 3239 *new_fdp = dup_fd(fd, max_fds);
3f4b0acefd818e Al Viro 2024-08-06 3240 if (IS_ERR(*new_fdp)) {
3f4b0acefd818e Al Viro 2024-08-06 3241 *new_fdp = NULL;
3f4b0acefd818e Al Viro 2024-08-06 @3242 return PTR_ERR(new_fdp);
^^^^^^^^^^^^^^^^
err = PTR_ERR(*new_fdp);
*new_fdp = NULL;
return err;
3f4b0acefd818e Al Viro 2024-08-06 3243 }
a016f3389c0660 JANAK DESAI 2006-02-07 3244 }
cf2e340f4249b7 JANAK DESAI 2006-02-07 3245
cf2e340f4249b7 JANAK DESAI 2006-02-07 3246 return 0;
cf2e340f4249b7 JANAK DESAI 2006-02-07 3247 }
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' 2024-08-13 8:00 [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' Dan Carpenter @ 2024-08-13 18:16 ` Al Viro 2024-08-14 1:03 ` Al Viro 0 siblings, 1 reply; 6+ messages in thread From: Al Viro @ 2024-08-13 18:16 UTC (permalink / raw) To: Dan Carpenter; +Cc: oe-kbuild, lkp, oe-kbuild-all, linux-fsdevel On Tue, Aug 13, 2024 at 11:00:04AM +0300, Dan Carpenter wrote: > 3f4b0acefd818e Al Viro 2024-08-06 3240 if (IS_ERR(*new_fdp)) { > 3f4b0acefd818e Al Viro 2024-08-06 3241 *new_fdp = NULL; > 3f4b0acefd818e Al Viro 2024-08-06 @3242 return PTR_ERR(new_fdp); > ^^^^^^^^^^^^^^^^ > err = PTR_ERR(*new_fdp); > *new_fdp = NULL; > return err; Argh... Obvious braino, but what it shows is that failures of that thing are not covered by anything in e.g. LTP. Or in-kernel self-tests, for that matter... ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' 2024-08-13 18:16 ` Al Viro @ 2024-08-14 1:03 ` Al Viro 2024-08-21 6:38 ` Shuah Khan 0 siblings, 1 reply; 6+ messages in thread From: Al Viro @ 2024-08-14 1:03 UTC (permalink / raw) To: Dan Carpenter; +Cc: oe-kbuild, lkp, oe-kbuild-all, linux-fsdevel, Shuah Khan On Tue, Aug 13, 2024 at 07:16:00PM +0100, Al Viro wrote: > On Tue, Aug 13, 2024 at 11:00:04AM +0300, Dan Carpenter wrote: > > 3f4b0acefd818e Al Viro 2024-08-06 3240 if (IS_ERR(*new_fdp)) { > > 3f4b0acefd818e Al Viro 2024-08-06 3241 *new_fdp = NULL; > > 3f4b0acefd818e Al Viro 2024-08-06 @3242 return PTR_ERR(new_fdp); > > ^^^^^^^^^^^^^^^^ > > err = PTR_ERR(*new_fdp); > > *new_fdp = NULL; > > return err; > > Argh... Obvious braino, but what it shows is that failures of that > thing are not covered by anything in e.g. LTP. Or in-kernel > self-tests, for that matter... FWIW, this does exercise that codepath, but I would really like to have kselftest folks to comment on the damn thing - I'm pretty sure that it's _not_ a good style for those. diff --git a/tools/testing/selftests/core/Makefile b/tools/testing/selftests/core/Makefile index ce262d097269..8e99f87f5d7c 100644 --- a/tools/testing/selftests/core/Makefile +++ b/tools/testing/selftests/core/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -g $(KHDR_INCLUDES) -TEST_GEN_PROGS := close_range_test +TEST_GEN_PROGS := close_range_test unshare_test include ../lib.mk diff --git a/tools/testing/selftests/core/unshare_test.c b/tools/testing/selftests/core/unshare_test.c new file mode 100644 index 000000000000..7fec9dfb1b0e --- /dev/null +++ b/tools/testing/selftests/core/unshare_test.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <linux/kernel.h> +#include <limits.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syscall.h> +#include <unistd.h> +#include <sys/resource.h> +#include <linux/close_range.h> + +#include "../kselftest_harness.h" +#include "../clone3/clone3_selftests.h" + +TEST(unshare_EMFILE) +{ + pid_t pid; + int status; + struct __clone_args args = { + .flags = CLONE_FILES, + .exit_signal = SIGCHLD, + }; + int fd; + ssize_t n, n2; + static char buf[512], buf2[512]; + struct rlimit rlimit; + int nr_open; + + fd = open("/proc/sys/fs/nr_open", O_RDWR); + ASSERT_GE(fd, 0); + + n = read(fd, buf, sizeof(buf)); + ASSERT_GT(n, 0); + ASSERT_EQ(buf[n - 1], '\n'); + + ASSERT_EQ(sscanf(buf, "%d", &nr_open), 1); + + ASSERT_EQ(0, getrlimit(RLIMIT_NOFILE, &rlimit)); + + /* bump fs.nr_open */ + n2 = sprintf(buf2, "%d\n", nr_open + 1024); + lseek(fd, 0, SEEK_SET); + write(fd, buf2, n2); + + /* bump ulimit -n */ + rlimit.rlim_cur = nr_open + 1024; + rlimit.rlim_max = nr_open + 1024; + EXPECT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlimit)) { + lseek(fd, 0, SEEK_SET); + write(fd, buf, n); + exit(EXIT_FAILURE); + } + + /* get a descriptor past the old fs.nr_open */ + EXPECT_GE(dup2(2, nr_open + 64), 0) { + lseek(fd, 0, SEEK_SET); + write(fd, buf, n); + exit(EXIT_FAILURE); + } + + /* get descriptor table shared */ + pid = sys_clone3(&args, sizeof(args)); + EXPECT_GE(pid, 0) { + lseek(fd, 0, SEEK_SET); + write(fd, buf, n); + exit(EXIT_FAILURE); + } + + if (pid == 0) { + int err; + + /* restore fs.nr_open */ + lseek(fd, 0, SEEK_SET); + write(fd, buf, n); + /* ... and now unshare(CLONE_FILES) must fail with EMFILE */ + err = unshare(CLONE_FILES); + EXPECT_EQ(err, -1) + exit(EXIT_FAILURE); + EXPECT_EQ(errno, EMFILE) + exit(EXIT_FAILURE); + exit(EXIT_SUCCESS); + } + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + +TEST_HARNESS_MAIN ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' 2024-08-14 1:03 ` Al Viro @ 2024-08-21 6:38 ` Shuah Khan 2024-08-22 0:15 ` Al Viro 0 siblings, 1 reply; 6+ messages in thread From: Shuah Khan @ 2024-08-21 6:38 UTC (permalink / raw) To: Al Viro, Dan Carpenter Cc: oe-kbuild, lkp, oe-kbuild-all, linux-fsdevel, Shuah Khan, Shuah Khan On 8/13/24 19:03, Al Viro wrote: > On Tue, Aug 13, 2024 at 07:16:00PM +0100, Al Viro wrote: >> On Tue, Aug 13, 2024 at 11:00:04AM +0300, Dan Carpenter wrote: >>> 3f4b0acefd818e Al Viro 2024-08-06 3240 if (IS_ERR(*new_fdp)) { >>> 3f4b0acefd818e Al Viro 2024-08-06 3241 *new_fdp = NULL; >>> 3f4b0acefd818e Al Viro 2024-08-06 @3242 return PTR_ERR(new_fdp); >>> ^^^^^^^^^^^^^^^^ >>> err = PTR_ERR(*new_fdp); >>> *new_fdp = NULL; >>> return err; >> >> Argh... Obvious braino, but what it shows is that failures of that >> thing are not covered by anything in e.g. LTP. Or in-kernel >> self-tests, for that matter... > > FWIW, this does exercise that codepath, but I would really like to > have kselftest folks to comment on the damn thing - I'm pretty sure > that it's _not_ a good style for those. Looks good to me. Would you be able to send a patch for this new test? > > diff --git a/tools/testing/selftests/core/Makefile b/tools/testing/selftests/core/Makefile > index ce262d097269..8e99f87f5d7c 100644 > --- a/tools/testing/selftests/core/Makefile > +++ b/tools/testing/selftests/core/Makefile > @@ -1,7 +1,7 @@ > # SPDX-License-Identifier: GPL-2.0-only > CFLAGS += -g $(KHDR_INCLUDES) > > -TEST_GEN_PROGS := close_range_test > +TEST_GEN_PROGS := close_range_test unshare_test > > include ../lib.mk > > diff --git a/tools/testing/selftests/core/unshare_test.c b/tools/testing/selftests/core/unshare_test.c > new file mode 100644 > index 000000000000..7fec9dfb1b0e > --- /dev/null > +++ b/tools/testing/selftests/core/unshare_test.c > @@ -0,0 +1,94 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#define _GNU_SOURCE > +#include <errno.h> > +#include <fcntl.h> > +#include <linux/kernel.h> > +#include <limits.h> > +#include <stdbool.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <syscall.h> > +#include <unistd.h> > +#include <sys/resource.h> > +#include <linux/close_range.h> > + > +#include "../kselftest_harness.h" > +#include "../clone3/clone3_selftests.h" > + > +TEST(unshare_EMFILE) > +{ > + pid_t pid; > + int status; > + struct __clone_args args = { > + .flags = CLONE_FILES, > + .exit_signal = SIGCHLD, > + }; > + int fd; > + ssize_t n, n2; > + static char buf[512], buf2[512]; > + struct rlimit rlimit; > + int nr_open; > + > + fd = open("/proc/sys/fs/nr_open", O_RDWR); > + ASSERT_GE(fd, 0); > + > + n = read(fd, buf, sizeof(buf)); > + ASSERT_GT(n, 0); > + ASSERT_EQ(buf[n - 1], '\n'); > + > + ASSERT_EQ(sscanf(buf, "%d", &nr_open), 1); > + > + ASSERT_EQ(0, getrlimit(RLIMIT_NOFILE, &rlimit)); > + > + /* bump fs.nr_open */ > + n2 = sprintf(buf2, "%d\n", nr_open + 1024); > + lseek(fd, 0, SEEK_SET); > + write(fd, buf2, n2); > + > + /* bump ulimit -n */ > + rlimit.rlim_cur = nr_open + 1024; > + rlimit.rlim_max = nr_open + 1024; > + EXPECT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlimit)) { > + lseek(fd, 0, SEEK_SET); > + write(fd, buf, n); > + exit(EXIT_FAILURE); > + } > + > + /* get a descriptor past the old fs.nr_open */ > + EXPECT_GE(dup2(2, nr_open + 64), 0) { > + lseek(fd, 0, SEEK_SET); > + write(fd, buf, n); > + exit(EXIT_FAILURE); > + } > + > + /* get descriptor table shared */ > + pid = sys_clone3(&args, sizeof(args)); > + EXPECT_GE(pid, 0) { > + lseek(fd, 0, SEEK_SET); > + write(fd, buf, n); > + exit(EXIT_FAILURE); > + } > + > + if (pid == 0) { > + int err; > + > + /* restore fs.nr_open */ > + lseek(fd, 0, SEEK_SET); > + write(fd, buf, n); > + /* ... and now unshare(CLONE_FILES) must fail with EMFILE */ > + err = unshare(CLONE_FILES); > + EXPECT_EQ(err, -1) > + exit(EXIT_FAILURE); > + EXPECT_EQ(errno, EMFILE) > + exit(EXIT_FAILURE); > + exit(EXIT_SUCCESS); > + } > + > + EXPECT_EQ(waitpid(pid, &status, 0), pid); > + EXPECT_EQ(true, WIFEXITED(status)); > + EXPECT_EQ(0, WEXITSTATUS(status)); > +} > + > +TEST_HARNESS_MAIN thanks, -- Shuah ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' 2024-08-21 6:38 ` Shuah Khan @ 2024-08-22 0:15 ` Al Viro 2024-08-22 4:12 ` Shuah Khan 0 siblings, 1 reply; 6+ messages in thread From: Al Viro @ 2024-08-22 0:15 UTC (permalink / raw) To: Shuah Khan Cc: Dan Carpenter, oe-kbuild, lkp, oe-kbuild-all, linux-fsdevel, Shuah Khan On Wed, Aug 21, 2024 at 12:38:48AM -0600, Shuah Khan wrote: > On 8/13/24 19:03, Al Viro wrote: > > On Tue, Aug 13, 2024 at 07:16:00PM +0100, Al Viro wrote: > > > On Tue, Aug 13, 2024 at 11:00:04AM +0300, Dan Carpenter wrote: > > > > 3f4b0acefd818e Al Viro 2024-08-06 3240 if (IS_ERR(*new_fdp)) { > > > > 3f4b0acefd818e Al Viro 2024-08-06 3241 *new_fdp = NULL; > > > > 3f4b0acefd818e Al Viro 2024-08-06 @3242 return PTR_ERR(new_fdp); > > > > ^^^^^^^^^^^^^^^^ > > > > err = PTR_ERR(*new_fdp); > > > > *new_fdp = NULL; > > > > return err; > > > > > > Argh... Obvious braino, but what it shows is that failures of that > > > thing are not covered by anything in e.g. LTP. Or in-kernel > > > self-tests, for that matter... > > > > FWIW, this does exercise that codepath, but I would really like to > > have kselftest folks to comment on the damn thing - I'm pretty sure > > that it's _not_ a good style for those. > > Looks good to me. Would you be able to send a patch for this new test? Umm... Send as in "mail somewhere specific", or as "push into vfs.git", or...? ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' 2024-08-22 0:15 ` Al Viro @ 2024-08-22 4:12 ` Shuah Khan 0 siblings, 0 replies; 6+ messages in thread From: Shuah Khan @ 2024-08-22 4:12 UTC (permalink / raw) To: Al Viro Cc: Dan Carpenter, oe-kbuild, lkp, oe-kbuild-all, linux-fsdevel, Shuah Khan, Shuah Khan On 8/21/24 18:15, Al Viro wrote: > On Wed, Aug 21, 2024 at 12:38:48AM -0600, Shuah Khan wrote: >> On 8/13/24 19:03, Al Viro wrote: >>> On Tue, Aug 13, 2024 at 07:16:00PM +0100, Al Viro wrote: >>>> On Tue, Aug 13, 2024 at 11:00:04AM +0300, Dan Carpenter wrote: >>>>> 3f4b0acefd818e Al Viro 2024-08-06 3240 if (IS_ERR(*new_fdp)) { >>>>> 3f4b0acefd818e Al Viro 2024-08-06 3241 *new_fdp = NULL; >>>>> 3f4b0acefd818e Al Viro 2024-08-06 @3242 return PTR_ERR(new_fdp); >>>>> ^^^^^^^^^^^^^^^^ >>>>> err = PTR_ERR(*new_fdp); >>>>> *new_fdp = NULL; >>>>> return err; >>>> >>>> Argh... Obvious braino, but what it shows is that failures of that >>>> thing are not covered by anything in e.g. LTP. Or in-kernel >>>> self-tests, for that matter... >>> >>> FWIW, this does exercise that codepath, but I would really like to >>> have kselftest folks to comment on the damn thing - I'm pretty sure >>> that it's _not_ a good style for those. >> >> Looks good to me. Would you be able to send a patch for this new test? > > Umm... Send as in "mail somewhere specific", or as "push into vfs.git", > or...? If you can send the patch to kselftest mailing test, I can take this through my tree. thanks, -- Shuah ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-08-22 4:12 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2024-08-13 8:00 [viro-vfs:work.fdtable 13/13] kernel/fork.c:3242 unshare_fd() warn: passing a valid pointer to 'PTR_ERR' Dan Carpenter 2024-08-13 18:16 ` Al Viro 2024-08-14 1:03 ` Al Viro 2024-08-21 6:38 ` Shuah Khan 2024-08-22 0:15 ` Al Viro 2024-08-22 4:12 ` Shuah Khan
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