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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-05 20:00:38 +0200 |
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| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-05 20:00:38 +0200 |
| commit | 96049c939b1916d80532630d63c14e04d5244f1d (patch) | |
| tree | 7fb9df428f074078e714f1e038210cdff887185a /results/classifier/user-mode-bugs/1394 | |
| parent | 40bbb77d4dfebff4f99c2f90b2c0db737b0ecc5a (diff) | |
| download | qemu-analysis-96049c939b1916d80532630d63c14e04d5244f1d.tar.gz qemu-analysis-96049c939b1916d80532630d63c14e04d5244f1d.zip | |
lock user-mode and semantic-bugs
Diffstat (limited to 'results/classifier/user-mode-bugs/1394')
| -rw-r--r-- | results/classifier/user-mode-bugs/1394 | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/results/classifier/user-mode-bugs/1394 b/results/classifier/user-mode-bugs/1394 new file mode 100644 index 000000000..db30c77f1 --- /dev/null +++ b/results/classifier/user-mode-bugs/1394 @@ -0,0 +1,63 @@ + + +Byte-swapping issue in getresuid on qemu-user-sparc64 +Description of problem: +When calling getresuid() in the big-endian sparc64 guest, the uid_t values are written with their 16-bit halves reversed. + +For example, the UID 0x000003e8 (1000) becomes 0x03e80000. +Steps to reproduce: +A minimal test case looks like this: +```c +#define _GNU_SOURCE +#include <stdio.h> +#include <sys/types.h> +#include <pwd.h> +#include <unistd.h> + +int main(int argc, char **argv) { + struct passwd *pw = getpwuid(geteuid()); + if (pw == NULL) { + perror("getpwuid failure"); + return 1; + } + printf("getpwuid()->pw_uid=0x%08x\n", pw->pw_uid); + + uid_t ruid = 0, euid = 0, suid = 0; + if (getresuid(&ruid, &euid, &suid) != 0) { + perror("getresuid failure"); + return 1; + } + printf("getresuid()->suid=0x%08x\n", suid); + + return 0; +} +``` + +Compile and run with: +``` +$ sparc64-linux-gnu-gcc -Wall -O0 -g -o sid-sparc64/test test.c +$ sudo chroot sid-sparc64 +[chroot] $ qemu-sparc64-static ./test +``` + +Alternatively, static compilation without a chroot is also possible (despite a warning about `getpwuid()`): +``` +$ sparc64-linux-gnu-gcc -static -Wall -O0 -g -o test test.c +$ qemu-sparc64-static ./test +``` + +Expected output: +``` +$ ./test +getpwuid()->pw_uid=0x000003e8 +getresuid()->suid=0x000003e8 +``` + +Actual output: +``` +$ ./test +getpwuid()->pw_uid=0x000003e8 +getresuid()->suid=0x03e80000 +``` +Additional information: +I'm not sure if this is a glibc, qemu or kernel issue, but it doesn't occur outside qemu. |